Publications by authors named "Setchell B"

216 Publications

The uptake of amino acids, in particular leucine, by isolated perfused testes of rats.

J Androl 2000 May-Jun;21(3):452-63

ARC Institute of Animal Physiology, Babraham, Cambridge, United Kingdom.

The uptake of amino acids by the isolated rat testis perfused with Krebs-Ringer solution with albumin has been studied using the single-passage, multiple-tracer technique with [14C]-mannitol as the reference tracer. When the perfusate contained no added amino acids, the uptake of [3H]-Leu was between 60% and 80% of the uptake of mannitol at all times after injection of the bolus; there was a small but significant uptake of some other amino acids studied (Ala, Gly, Glu, and Asp); and with Ala, Glu, and Asp, uptake increased slightly in increasing times after injection. There was no significant uptake of Arg. The uptake of Leu could be decreased by the inclusion of nonradioactive Leu in the perfusate, and the Km and Vmax of the transport were 0.067 mM and 19.5 nmole/(g x min), respectively. The Km value is similar to that for transport into brain and much less than the values obtained in other tissues for the related amino acid Phe, which is transported by the same L system. The transport of L-Leu in the testis was also inhibited by L-Phe or D-Phe, D-Leu, and by the synthetic amino acid Bch, the characteristic marker for the L system, but was only slightly reduced if the perfusate was free of sodium, as is expected for the L system. By autoradiography after fixation by perfusing with glutaraldehyde, the transport of Leu could be localized to the endothelial cells of the larger vessels of the testicular microvasculature.
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July 2000

The permeability of the microvasculature of the perfused rat testis to small hydrophilic substances.

J Androl 2000 May-Jun;21(3):444-51

ARC Institute of Animal Physiology, Babraham, Cambridge, United Kingdom.

The permeability-surface area products (PS) for sodium, Cr-EDTA, and cyanocobalamine (CoB12) have been determined in isolated perfused rat testes, using the single-passage multiple tracer technique, with albumin as the reference tracer. The validity of using albumin was established from its recovery in the perfusate leaving the testis, which was 98.73+/-0.48% of that for Cr-labeled red cells. The PS values obtained for Na, Cr-EDTA, and CoB12 were correlated with perfusate flow, both below and above levels that were equivalent to normal rates of blood flow in the testis (0.3 mL/[g x min]). The values found at the highest flow rates obtained (between 2.7 and 3.5 mL/[g x min]) were 2230+/-240 microL/(g x min) (n = 8) for sodium, 1460+/-140 microL/(g x min) (n = 7) for Cr-EDTA, and 850+/-80 microL/(g x min) (n = 7) for CoB12. These values are similar to those reported at equivalent flow rates for heart muscle and greater than those reported for skeletal muscle, both of which have unfenestrated capillaries similar to testis, but are less than the values for pancreas and salivary gland, which have fenestrated capillaries and are similar to most other endocrine tissues. However, the permeability coefficients for these markers in the testis (calculated using published values for the surface area of the testicular microvasculature) appear to be considerably greater than for any other tissue studied thus far. By extrapolating extraction values, either linearly or logarithmically, to obtain maximal values for PS for Cr-EDTA and CoB12, and comparing the ratio of these PS area values with the ratio of the diffusion coefficients of these molecules, it can be calculated that the equivalent pore radius for the testicular endothelium is between 5 and 6 nm, comparable to those calculated for other nonfenestrated endothelia.
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July 2000

Constitutive and inducible production of proinflammatory cytokines by the rat testis.

Andrologia 2000 Jan;32(1):63-4

Department of Woman and Child Health, Astrid Lindgren Children's Hospital, Turku, Finland.

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January 2000

Effect of compatible solutes and diluent composition on the post-thaw motility of ram sperm.

Reprod Fertil Dev 1998 ;10(4):347-57

Department of Animal Science, The University of Adelaide, Glen Osmond, SA, Australia.

The effect of the compatible solutes proline, glycine betaine and trehalose in Tris-based diluents at varying pH, concentrations of egg yolk or glycerol on the post-thaw motility characteristics and fertility of ram sperm was examined. In addition, the amino acid glycine was compared with proline, glycine betaine and a standard Tris-based diluent. Post-thaw motility was assessed using a Hamilton-Thorn motility analyser. In the presence of glycerol and egg yolk, proline and glycine betaine improved the post-thaw motility characteristics of ram sperm. Regardless of the pH of the diluent at which semen was frozen, the percentage of motile sperm was higher when frozen in the presence of proline or glycine betaine than in their absence, whereas proline and glycine betaine only improved the progressive and rapid percentages of sperm for semen frozen in diluents at pH lower than 7.0. When semen was frozen in the absence of egg yolk or glycerol all the motility characteristics were reduced. Increasing the concentration of egg yolk in the diluent from 5% to 10, 15 or 20% had no effect on the post-thaw motility of sperm. The addition of 27 mM of proline or glycine betaine to the diluent also improved post-thaw motility. However, at a concentration of 81 mM, proline and glycine betaine had a detrimental effect on the percentage of motile sperm. Trehalose had no effect on the motility of sperm frozen in glycerol-containing diluents, but motility was lower after cryopreservation in glycine than in Tris-, proline- or glycine betaine-based diluents. There were no differences in the fertility of sperm frozen in Tris-, proline or glycine betaine diluents after cervical or laparoscopic insemination of ewes.
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http://dx.doi.org/10.1071/r98053DOI Listing
August 1999

Fertility and its relationship to motility characteristics of spermatozoa in ewes after cervical, transcervical, and intrauterine insemination with frozen-thawed ram semen.

J Androl 1999 Mar-Apr;20(2):280-8

Department of Animal Science, University of Adelaide, Glen Osmond, Australia.

The fertility of ewes after artificial insemination and the relationship between fertility and motility characteristics assessed by a computerized motility analysis system were examined with ram semen frozen in diluents reported to improve postthaw motility. The percentages of motile and progressive spermatozoa were better when frozen in proline- or glycine betaine-containing or HEPES-based, rather than Tris-based, diluents (P < 0.01). The fertility of spermatozoa frozen in diluents containing proline or glycine betaine was slightly reduced, whereas when both compatible solutes were present, the reduction was more pronounced, in comparison with semen frozen in Tris- or HEPES-based diluents (9.5 versus 71.1 and 66.6%; P < 0.01). Fertility of frozen-thawed spermatozoa was higher after laparoscopic insemination than after cervical or transcervical insemination (P < 0.01). Similarly, higher fertility was obtained after cervical insemination with fresh than with frozen-thawed semen (32.4 versus 11.3%; P < 0.01). Furthermore, loss of embryos was lower after laparoscopic insemination of ewes with semen frozen in a Tris diluent than with semen frozen in proline diluents, in glycine betaine diluents, or in proline-plus-glycine betaine diluents (0.0 versus 26.0, 38.5, and 60.0%; P < 0.001). A wide variation in the postthaw percentage of motile (31.6-59.7%) and progressive (22.6-43.1%) spermatozoa and in the fertility of spermatozoa from individual rams was also observed after laparoscopic (29.2-59.7%) or cervical insemination (8.7-30.5%). Postthaw motility results from immediately after thawing and fertility results from experiments where intrauterine insemination was performed with semen frozen in proline- or glycine betaine-containing or HEPES- or Tris-based diluents were pooled and subjected to a pairwise correlation procedure. The correlation analysis showed relationships between some of the motility characteristics (P < 0.01), but there were no relationships between the motility characteristics and fertility.
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July 1999

The Parkes Lecture. Heat and the testis.

Authors:
B P Setchell

J Reprod Fertil 1998 Nov;114(2):179-94

Department of Animal Science, University of Adelaide, Australia.

The evidence for the lower temperature of the testes of many mammals is summarized, and the reasons suggested for the descent of the testes into a scrotum are discussed. Descriptions are given of the various techniques used for studying the effects of heat on the testis, whole body heating, local heating of the testes (by inducing cryptorchidism, scrotal insulation or immersion of the scrotum in a water bath), and heating of tissue or cell preparations in vitro. The effects of heat are discussed, effects on the testis (weight, histology, physiology, biochemistry and endocrinology), on the numbers and motility of spermatozoa in rete testis fluid and semen, on fertilizing ability of spermatozoa and on the subsequent development of the embryos produced when spermatozoa from heated testes are used to fertilize normal ova. The possible mechanisms for the damaging effects of heat are discussed, as well as the importance of heat-induced abnormalities in male reproduction in domestic animals and humans.
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http://dx.doi.org/10.1530/jrf.0.1140179DOI Listing
November 1998

Secretion of D-aspartic acid by the rat testis and its role in endocrinology of the testis and spermatogenesis.

FEBS Lett 1998 Sep;436(1):23-7

Department of Biochemistry and Molecular Biology, Zoological Station of Naples, Napoli, Italy.

The D-isomer of aspartic acid (D-Asp) has been found in rat testes. In the present study, samples of testicular venous blood plasma, rete testis fluid, interstitial extracellular fluid, luminal fluid from the seminiferous tubules, testicular parenchymal cells, epididymal spermatozoa and peripheral blood plasma were collected and analyzed for D-Asp by two methods, an enzymatic and a chromatographic HPLC method. The two methods gave very similar results for all samples. The highest concentrations of D-Asp (about 120 nmol/ml) were found in testicular venous blood plasma, with slightly lower concentrations in rete testis fluid (95 nmol/ml) and epididymal spermatozoa (80 nmol/g wet weight). Lower levels were found in testicular parenchymal cells (which would comprise mostly spermatids and spermatocytes), luminal fluid from the seminiferous tubules and interstitial extracellular fluid (26, 23 and 11 nmol/ml respectively). However, these values were all higher than those for peripheral blood plasma (6 nmol/ml). It would appear that D-Asp is being secreted by the testis mostly into the venous blood, passing thence into the rete testis fluid and being incorporated into the spermatozoa at the time or after they leave the testis. The distribution of D-Asp is thus quite different from that of testosterone, and its role and the reason for its high concentration in the male reproductive tract remain to be elucidated.
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http://dx.doi.org/10.1016/s0014-5793(98)01087-4DOI Listing
September 1998

Transient retardation in embryo growth in normal female mice made pregnant by males whose testes had been heated.

Hum Reprod 1998 Feb;13(2):342-7

Department of Animal Science, University of Adelaide (Waite), Glen Osmond, S.A., Australia.

In three separate experiments, using three different strains of mice, when normal females were mated by males whose testes had been heated once to 42 degrees C for 20 min, the embryos at 10.5 days post-coitum were approximately 20% smaller than control embryos. In one experiment, the difference was still present, although proportionately less, at 15.5 and 18.5 days and, in another experiment, a difference could be seen in 11.5 and 13.5 day old embryos but not in 12.5, 14.5, 15.5 or 18.5 day old embryos. The frequency of mating and pregnancy rates were unaffected. In one experiment, the time available for mating was restricted to 4 h instead of overnight, without effect on the result. In another experiment, other males were heated for 30 min, and these showed a period of infertility from 10 to 32 days later, preceded and followed by the production of smaller than normal embryos; litter size was also reduced in the period after the return of fertility in these animals. The yolk sacs and the trophoblasts of the embryos sired by the heated males were also slightly smaller than those sired by the controls in the two experiments in which these were measured. The pattern of weight reduction is thus different from that seen in gynogenetic embryos or when the gene for insulin-like growth factor (IGF)-II is disrupted, and suggests a reduction in embryo growth at the earlier stages, with compensatory growth occurring later in pregnancy.
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http://dx.doi.org/10.1093/humrep/13.2.342DOI Listing
February 1998

Reduction in fluid secretion by rat testis by drugs that block potassium channels.

J Reprod Fertil 1998 Jan;112(1):87-94

Department of Animal Science, University of Adelaide, Australia.

The effect of two class III antiarrhythmic drugs (Almokalant, Astra-Hässle and Dofetilide, Pfizer) on fluid secretion by rat testes has been examined. Both drugs reduced fluid secretion, whether this was measured by the amount of rete testis fluid that could be collected 22 h after unilateral efferent duct ligation, or by the difference in mass between the ligated and unligated testes, or by the difference in amount of supernatant fluid after the parenchyma of the ligated and unligated testes had been dispersed and centrifuged. The secretion of potassium, calculated from the amount of potassium in the supernatant fluids from the ligated and unligated testes was also reduced by the drugs, whereas the secretion of androgen-binding protein and inositol was unaffected. The concentration of potassium in the secreted fluid, calculated from the amount and composition of the supernatant fluids, was not affected by treatment of the rats with Almokalant, but was increased in rats treated with Dofetilide and, in these, the concentration of sodium was reduced and that of magnesium and inositol was increased and the concentration of total protein was unaffected. The concentration of androgen-binding protein in secreted fluid was increased in rats treated with Almokalant, while the concentration of testosterone was unaffected. Histological examination of testes from treated rats revealed phagocytosis of stage 19 spermatids in tubules at stages VIII-IX after 2 days, at stages IX-XI after 4 days and at stages VIII-XIV after 7 days, apparently owing to an effect on spermiation. It appears that these drugs interfere with potassium-mediated fluid secretion by the testis, leading to the other changes seen.
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http://dx.doi.org/10.1530/jrf.0.1120087DOI Listing
January 1998

Sperm counts in semen of farm animals 1932-1995.

Authors:
B P Setchell

Int J Androl 1997 Aug;20(4):209-14

Department of Animal Science, University of Adelaide, Glen Osmond, Australia.

In some countries, sperm counts in normal human semen seem to have declined over the last 50 years. If this decline is real and due to environmental factors, falls might also be seen in sperm numbers in the semen of farm animals. Sperm counts are available for bull, boar and ram from the early 1930s, obtained using techniques similar to those used for human semen. Data have been obtained from the literature between 1932 and 1995 from 137 studies involving bulls, 76 involving boars and 130 involving rams. All were normal adult animals, from which semen was collected regularly but at a frequency which would not be likely to cause a fall in sperm counts. The references were obtained systematically from Animal Breeding Abstracts, and where possible the original articles were consulted to obtain mean values for each study; where the original reference was not easily obtainable, values were taken from the abstract. The bull data showed no correlation of sperm count with year of publication (r2 = 0.000), for the boars there was a slight but non-significant positive correlation (r2 = 0.041), and for the sheep there was a slight, but significant, rise in sperm counts with time (r2 = 0.124 for sperm counts and 0.126 for total sperm per ejaculate; not all authors gave both values). It would appear that, if the fall in human sperm counts is real, then it must be due to something which is not affecting farm animals.
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http://dx.doi.org/10.1046/j.1365-2605.1997.00054.xDOI Listing
August 1997

Microvascular permeability to the F(ab')2 fragment of IgG in the male rat reproductive tract at puberty.

J Reprod Immunol 1997 Feb;32(3):221-40

Department of Anatomy, University of Turku, Finland.

Development of contraceptive vaccines has recently raised much interest following the cloning of the sperm and oocyte components involved in the sperm-oocyte interaction. The main difficulty of immunocontraception in the male is the poor access of antibodies to the luminal compartment. As recent literature suggests that many substances are transported to the testis by receptor-mediated or fluid-phase transcytosis, the dependence of the transport of IgG on the Fc receptor was studied in the present investigation by comparing the penetration of whole IgG and the F(ab')2 fragment of IgG to the testis and epididymis. The maximum volume of distribution (Veq) for the F(ab')2 fragment was significantly higher than that for whole IgG in the testis of 30-60-day old rats, in the caput and cauda of 30- and 45-day old rats and the corpus of 45-day old rats. The speeds at which equilibrium between tissue extracellular fluid and serum was reached (K) for the F(ab')2 fragment and whole IgG were significantly different in the testicular capsule of the 60-day old, in the caput and corpus of the 45- and 60-day old and in the cauda of the 45-day old rats. The microvascular permeabilities (PE) to the F(ab')2 fragment were more than 2-fold higher than those to whole IgG in the testis of the 20-, 45- and 60-day old, in the testicular capsule of the 20- and 45-day old, in the caput of 20-, 30- and 60-day old and in the corpus of 20-day old rats. The PE to whole IgG was more than 2-fold higher than that to the F(ab')2 fragment in the cauda of the 45-day-old rats. The PE to the F(ab')2 fragment increased steadily from 20 to 60 days of age in the testis and caput, but in the corpus there was a more abrupt increase between 30 and 45 days of age. In the cauda, PE remained in the same range of magnitude throughout pubertal development. These results suggest that the F(ab')2 fragment reaches the lumen of the reproductive tract more easily than whole IgG from 30 days of age onwards in the testis, whereas in the caput, corpus and cauda epididymidis the rate at which F(ab')2 fragment reaches the lumen increases only temporarily at the time of appearance of spermatozoa in the lumen. Transport of IgG to the male reproductive tract is thus unlikely to be mediated by Fc receptors.
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http://dx.doi.org/10.1016/s0165-0378(96)01003-0DOI Listing
February 1997

Epididymal compounds and antioxidants in diluents for the frozen storage of ram spermatozoa.

Reprod Fertil Dev 1997 ;9(7):689-96

Department of Animal Science, The University of Adelaide, Glen Osmond, SA, Australia.

The epididymal compounds taurine, hypotaurine and inositol, and the antioxidants carnosine and ascorbic acid, were added to Tris-based diluents containing varying concentrations of glycerol, and their effect on the post-thaw motility characteristics and fertility of ram spermatozoa was examined. Overall, the post-thaw motility characteristics of spermatozoa were better when semen was frozen in the presence rather than in the absence of glycerol. Only taurine protected spermatozoa during cryopreservation; the presence of 25 mM or 50 mM taurine significantly improved the post-thaw percentage of motile spermatozoa but this had no effect on fertility after cervical or laparoscopic insemination of ewes. Increasing the concentration of taurine to more than 100 mM significantly reduced the percentage of motile spermatozoa, compared with the lower concentrations of the amino acid. The presence of more than 50 mM carnosine or ascorbic acid significantly reduced all motility characteristics compared with the control diluent. Given that hypotaurine, carnosine, or ascorbic acid did not improve post-thaw motility, the cryoprotective effect of taurine may be attributable to its osmoregulation rather than to its antioxidant properties.
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http://dx.doi.org/10.1071/r97045DOI Listing
August 1998

Human reproduction. The missing parts of the puzzle.

Authors:
B P Setchell

Adv Exp Med Biol 1997 ;424:1-15

Department of Animal Science, University of Adelaide, Glen Osmond, Australia.

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January 1998

The penetration of chromium-EDTA from blood plasma into various compartments of rat testes as an indicator of function of the blood-testis barrier after exposure of the testes to heat.

J Reprod Fertil 1996 Jan;106(1):125-33

Department of Animal Science, University of Adelaide, Waite, Australia.

The concentration of chromium51-EDTA in blood plasma after an intravenous infusion was found to be about 40 times that present in rete testis fluid and 20 times that in the additional seminiferous tubular fluid resulting from ligation of the efferent ducts. These values indicate the effectiveness of the blood-testis barrier to small water-soluble molecules, like Cr-EDTA. The volume of distribution in microlitres of Cr-EDTA in the parenchyma was about 60% of the volume of the interstitial tissue as determined on frozen sections by morphometry, and was similar, or slightly less, in the ligated testes, compared with the unligated testes. Heating the testes to 43 degrees C for 30 min led to the expected reduction several days later in testis mass, but the volume of distribution of Cr-EDTA was no greater than that in the testes of control rats, and the ratio of Cr-EDTA space to interstitial tissue was not different, while the concentration of Cr-EDTA in the additional seminiferous tubular fluid increased only slightly as testis mass fell. These results indicate that the blood-testis barrier was only slightly less effective, if changed at all, during the period of spermatogenic disruption following local heating of the testis.
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http://dx.doi.org/10.1530/jrf.0.1060125DOI Listing
January 1996

Effect of testicular temperature on vasomotion and blood flow.

Int J Androl 1995 Jun;18(3):120-6

Department of Urology, University of Umea, Sweden.

Vasomotion (spontaneous rhythmic variations in blood flow) has been demonstrated in the parenchyma of the testes of anaesthetized rats, using a laser-Doppler flow probe. As the temperature of the testis was increased, mean blood flow showed no change, but the frequency of vasomotion increased and its amplitude decreased, until vasomotion disappeared between 36 degrees C and 42 degrees C. As the testis was then cooled, vasomotion reappeared, and increased in amplitude and decreased in frequency as the temperature fell. In control rats, in which the temperature of the testes was maintained at normal scrotal temperature of about 33 degrees C, there no changes in vasomotion over an equivalent period. In both groups of rats, when the temperature of the testes was then allowed to fall below normal scrotal temperature, the amplitude of vasomotion increased and its frequency decreased even further, without any change in mean blood flow. Capillary blood flow was also measured with microspheres at the end of the experiment, when testicular temperature was between 19 degrees C and 27 degrees C, and there was no difference between the cooled and control testes or epididymides.
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http://dx.doi.org/10.1111/j.1365-2605.1995.tb00397.xDOI Listing
June 1995

Effect of active immunization against oestradiol in developing ram lambs on plasma gonadotrophin and testosterone concentrations, time of onset of puberty and testicular blood flow.

J Reprod Fertil 1995 May;104(1):7-16

Department of Animal Sciences, Waite Agricultural Research Institute, University of Adelaide, South Australia.

Merino ram lambs were actively immunized against oestradiol-6 (o-carboxy methyl) oxime-BSA conjugate at 14 weeks of age and received a booster injection 4 weeks later. This treatment led to an increase in plasma concentrations of gonadotrophin and tended to enhance the increase in testicular volume until 26 weeks of age; however, testis size and mass at time of castration (30 weeks of age) were similar to values in BSA-immunized lambs. Detrimental effects were observed in some oestradiol-immunized ram lambs, for example a steep decline in testicular volume towards the end of the experiment, the presence of large vacuoles within the seminiferous epithelium and, in one lamb, few germ cell at 30 weeks of age. Testicular blood plasma flow was significantly reduced in oestradiol-immunized lambs (P < 0.01). The steroidogenic function of the testis was markedly enhanced in oestradiol-immunized lambs as reflected by high plasma concentrations of testosterone measured at 22, 26 and 30 weeks of age and by high testosterone production calculated from blood flow and venous-arterial differences at 30 weeks of age. Nevertheless, total live mass gain over the 16 week study was not increased in oestradiol-immunized lambs. Testicular biopsies were taken at 22 and 26 weeks of age in half of the lambs in each treatment group. Testicular volume measured at castration was decreased in control lambs in which biopsies were taken (P < 0.05), and plasma concentrations of testosterone measured at 30 weeks of age were significantly lower in oestradiol-immunized lambs in which biopsies were taken (P < 0.02) compared with lambs in which no biopsy had been taken. It is concluded that active immunization against oestradiol in ram lambs does not advance the time of onset of puberty and does not confer any reproductive or maturational advantages.
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http://dx.doi.org/10.1530/jrf.0.1040007DOI Listing
May 1995

Effect of active immunization against testosterone on plasma gonadotrophin concentrations, spermatogenic function, testicular blood flow, epididymis mass and mating behaviour in adult rams.

J Reprod Fertil 1995 May;104(1):17-26

Department of Animal Sciences, Waite Agricultural Research Institute, University of Adelaide, South Australia.

The long-term effects of active immunization against testosterone were studied in rams, with particular reference to blood concentrations of gonadotrophin and testosterone, spermatogenesis, testis blood flow and mating behaviour. Ten 18-month-old Merino rams, kept on pasture, were studied for 1 year. Every 2 months, five rams received injections of BSA in Freund's adjuvant and five other rams were treated with testosterone-3(o-carboxymethyl)oxime-BSA as immunogen. Anti-testosterone antibodies (mean titre: 1:4484 +/- 582, after boosters) were maintained in the circulation, with the help of regular booster injections. In time, immunization reduced live mass in testosterone-immunized rams; however, there was no effect on testicular volume throughout the whole study. In testosterone-immunized rams, significantly higher concentrations of gonadotrophins were found in jugular venous plasma, as well as increased concentrations of total plasma testosterone. LH pulse frequency, amplitude and nadir were increased significantly in testosterone-immunized rams. After 12 months of immunization, no differences were found in the number of spermatozoa per ejaculate, in daily sperm production or in testis mass between the two groups of rams; however, testicular blood flow (per testis) and epididymis mass were significantly reduced in testosterone-immunized rams. Testosterone immuno-neutralization also resulted in a significant reduction in the number of mounts culminating in ejaculation performed during a 10 min trial carried out on a number of occasions during the experiment. Additional information on these rams was collected 3 months after castration. However, there were no significant differences in mean plasma LH and FSH concentrations, either before, or after, a single GnRH injection between the two groups of rams at this time.
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http://dx.doi.org/10.1530/jrf.0.1040017DOI Listing
May 1995

History of the Australian Society for Reproductive Biology 1968-1994.

Authors:
B P Setchell

Reprod Fertil Dev 1995 ;7(5):961-6

Department of Animal Science, University of Adelaide, Glen Osmond, Australia.

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http://dx.doi.org/10.1071/rd9950961DOI Listing
October 1996

X-Y chromosome dissociation in mice and rats exposed to increased testicular or environmental temperatures.

Reprod Fertil Dev 1995 ;7(5):1117-21

Department of Animal Science, University of Adelaide, Australia.

Heating the testes, scrota and tails of mice and rats by immersion in a water bath at 42 degrees C for 20 min caused an increased percentage of X-Y univalents in meiotic preparations made after 6 and 12 days respectively. It was also confirmed that exposing mice of a cool-adapted strain to an environment at 33 degrees C for 5 days resulted in an increase in the percentage of X-Y and autosomal univalents in meiotic preparations made after a recovery period of 2 days. Mice of a strain adapted to living at 33 degrees C also showed a higher rate of X-Y dissociation than control cool-adapted mice, but a lower frequency of autosomal univalents than cool-adapted mice exposed to the hot environment. The testes of the heat-adapted mice were even more sensitive than the testes of cool-adapted mice to the effects of local heating, as judged by the fall in testis weight 21 days afterwards.
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http://dx.doi.org/10.1071/rd9951117DOI Listing
October 1996

Failure of thyroid allografts to function in the testes of cynomolgous monkeys.

J Reprod Immunol 1995 Jan;28(1):75-80

Pediatric Endocrinology Unit, Karolinska Hospital, Stockholm, Sweden.

Allografts of thyroid were placed into one testis of 8 cynomolgous monkeys. None of these had accumulated significant amounts of radioactive iodide 28 days later, whereas autografts of thyroid placed in the other testis of 6 of these monkeys did so in 5 cases out of the 6. Autografts of thyroid placed subcutaneously in these 6 monkeys also accumulated iodide in the same 5 animals, but subcutaneous allografts failed in all 6 monkeys in which these were done. These results suggest that there is no immune privilege for grafts in the primate testis, which in this regard resembles more the testis of the ram, rather than that of rodents.
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http://dx.doi.org/10.1016/0165-0378(94)00897-gDOI Listing
January 1995

Investigating local regulation of the testes of ruminants.

J Reprod Fertil Suppl 1995 ;49:309-19

Department of Animal Science, University of Adelaide, Waite Agricultural Research Institute, Glen Osmond, South Australia.

In addition to endocrine regulation by the gonadotrophic hormones, the functions of the testes are regulated locally by paracrine and autocrine factors. Some attempts have been made to isolate cells from the testes of immature bulls and rams for investigation of cell function in vitro. However, most studies have used in vitro cultures of cells isolated from the testes of rats and a large variety of factors have been identified as potential local regulators. This review examines the importance of Sertoli cell-germ cell interactions, Leydig cells and steroidogenesis, blood flow and vascular permeability, and cytokines and immune cells as local regulators of the testes. The small amount of work undertaken on the testes of ruminants is reviewed together with approaches such as the transilluminated dissection of staged seminiferous tubules and in vivo cell depletion models used with rats. The suitability and limitation of these approaches for ruminants are considered, and immunological and molecular probes are raised as options for future investigations of the local regulation of the testes of ruminants.
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August 1995

Possible physiological bases for contraceptive techniques in the male.

Authors:
B P Setchell

Hum Reprod 1994 Jun;9(6):1081-7

Department of Animal Sciences, University of Adelaide, Australia.

Aspects of the physiology of the testis and epididymis are discussed which might be relevant to future methods of contraception in the male. These include the blood-testis barriers, both at the tubular and vascular level, testicular and scrotal thermoregulation and maturation of spermatozoa in the epididymis. Possible adverse consequences of interfering with spermatogenesis are also considered, such as reduced endocrine responsiveness of the testis, increased incidence of genetic abnormalities and abnormal development of embryos produced by sub-fertile males.
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http://dx.doi.org/10.1093/oxfordjournals.humrep.a138637DOI Listing
June 1994

Effects of a single brief period of moderate heating of the testes on seminiferous tubules in hypophysectomized rams treated with pituitary extract.

J Reprod Fertil 1993 Mar;97(2):381-7

INRA, URA CNRS 1291, Nouzilly, Monnaie, France.

An experiment was conducted to examine the appearance of the seminiferous tubule 20 days after a single exposure of the testes of rams to a scrotal temperature of about 42 degrees C for 45 min. Ten of the animals were surgically hypophysectomized and five were simultaneously heated; these rams were treated twice a day with ovine pituitary extract to avoid modifications in the negative feedback from the testes to the pituitary and consequent changes in gonadotrophin secretion. Six intact rams (three heated and three unheated) were also studied. The pituitary extract significantly increased the testis weight and spermatogonial multiplications from A1 spermatogonia onwards. Twenty days after the heat treatment, testis weight was significantly reduced by heating; both tubular and intertubular tissues were affected. The total length of seminiferous tubules per testis was not modified, whereas the mean seminiferous tubule diameter was significantly reduced after heating. The total number of Sertoli cells per testis was not significantly modified, while their mean cross-sectional nuclear area was significantly reduced by heat treatment. A decrease in the number of all germ cells except A0 spermatogonia, from A1 spermatogonia onwards, was observed. The number of round spermatids decreased by 95 and 90%, slightly more than the diplotene primary spermatocytes (76 and 77%) and elongated spermatids (79 and 85%) in hypophysectomized pituitary extract-treated and intact rams, respectively. Round and elongated spermatids would be derived from germ cells that were respectively leptotene and young pachytene primary spermatocytes at the time of heating, whereas diplotene primary spermatocytes would have been type B spermatogonia.(ABSTRACT TRUNCATED AT 250 WORDS)
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http://dx.doi.org/10.1530/jrf.0.0970381DOI Listing
March 1993

Epididymal constituents and related substances in the storage of spermatozoa: a review.

Reprod Fertil Dev 1993 ;5(6):601-12

Department of Animal Sciences, Waite Agricultural Research Institute, University of Adelaide, Glen Osmond, Australia.

In vertebrate animals, the duration of storage of viable spermatozoa in the epididymis varies from a few hours in birds to many months in reptiles and bats. The available information on the unusual composition of the epididymal luminal fluid is summarized, and the effect of the various constituents on sperm motility is described. Spermatozoa would probably be best stored in an immotile state and some constituents of epididymal luminal fluid may be able to inhibit the motility of mammalian spermatozoa during storage in vitro. If this effect can then be removed at the time of insemination, by changing the spermatozoa to a different medium, such a procedure may allow storage of spermatozoa at room or even body temperature for extended periods.
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http://dx.doi.org/10.1071/rd9930601DOI Listing
July 1998

Acute effects of cholestatic and choleretic bile salts on vasopressin- and glucagon-induced hepato-biliary calcium fluxes in the perfused rat liver.

Biochem J 1992 Apr;283 ( Pt 2):575-81

Division of Biochemistry and Molecular Biology, School of Life Sciences, Faculty of Science, Australian National University, Canberra.

The effects were investigated of the choleretic bile salt glycoursodeoxycholate (G-UDCA) and of the cholestatic bile salt taurochenodeoxycholate (T-CDCA) on changes in perfusate Ca2+, glucose and oxygen and in bile calcium and bile flow induced by the administration of (a) vasopressin, (b) glucagon and (c) glucagon plus vasopressin together to the perfused rat liver [Hamada, Karjalainen, Setchell, Millard & Bygrave (1992) Biochem. J. 281, 387-392]. G-UDCA itself increased the secretion of calcium in the bile several-fold, but its principal effect was to augment each of the above-mentioned metabolic events except glucose and oxygen output; particularly noteworthy was its ability to augment the 'transients' in bile calcium and bile flow seen immediately after the administration of vasopressin with or without glucagon. T-CDCA, by contrast, produced opposite effects and attenuated all of the parameters measured, and in particular the transients in bile calcium and bile flow. The data provide evidence of a strong correlation between calcium fluxes occurring on both the sinusoidal and the bile-canalicular membranes and that all are modifiable by glucagon, Ca(2+)-mobilizing hormones and bile salts.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1131074PMC
http://dx.doi.org/10.1042/bj2830575DOI Listing
April 1992

Increased flow of testicular blood plasma during local heating of the testes of rams.

J Reprod Fertil 1992 Mar;94(2):345-52

Department of Animal Sciences, Waite Agricultural Research Institute, University of Adelaide, Glen Osmond, Australia.

After removal of the scrotal skin, one testis of each of 12 adult anaesthetized rams was kept at 33 degrees C for 60 min, then heated either to 36 degrees C for 60 min and then to 39 degrees C for 60 min, or to 36 degrees C for 120 min and then returned to 33 degrees C for 100 min, while the other testis was maintained at 33 degrees C. Flow of testicular blood plasma was measured every 10 min using the technique of dilution of sodium p-aminohippurate. When the temperature of the testis was raised to 36 degrees C, flow of blood plasma gradually increased and reached a higher than normal rate at the end of the first hour, without any further increase during the second hour. The increase in mean flow rate was 25.8 +/- 3.4% (mean +/- SEM) during the second hour at 36 degrees C, and 77.1 +/- 12.8% during the hour at 39 degrees C, compared with the respective values at 33 degrees C. No significant changes were seen in testicular lymph flow determined by collection for 10 min in four rams at 36 degrees C (60 min) and then at 39 degrees C (60 min). These results are different from those from earlier studies in which total blood flow was unchanged when the scrotum and testes were heated. The difference could be related either to lack of heating of the scrotum or to the lower temperatures used in the present study.(ABSTRACT TRUNCATED AT 250 WORDS)
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http://dx.doi.org/10.1530/jrf.0.0940345DOI Listing
March 1992

Effects of heating the testes and epididymides of rams by scrotal insulation on fertility and embryonic mortality in ewes inseminated with frozen semen.

J Reprod Fertil 1992 Mar;94(2):337-43

Department of Animal Sciences, Waite Agricultural Research Institute, University of Adelaide, Glen Osmond, Australia.

Fertilization rate and embryonic mortality were assessed in 636 ewes inseminated in each uterine horn with 50 x 10(6) frozen spermatozoa from four control rams and from four rams submitted to a moderate (1.4-2.2 degrees C), but repeated, intermittent (16 h/day for 21 consecutive days) increase in their subcutaneous scrotal temperature by means of scrotal insulation. Pregnancy was assessed twice in each ewe from concentration of progesterone in blood plasma at 17 days and by ultrasound at 65 days after insemination. No differences were observed in the pregnancy rate at 17 days between ewes inseminated with semen collected from control rams (56.0, 65.2, 66.7 and 60.3%) and from heated rams (60.6, 71.8, 63.6 and 48.2%) before or after 4, 15 and 21 days of heating, respectively. In contrast, the rate of embryonic mortality between 17 and 65 days after insemination was significantly higher at days 4, 15 and 21 in the heated rams (78.7, 78.6 and 93%) than in the control rams (55, 59 and 65.7%). These results indicate that an intermittent slight, but repeated, increase in the subcutaneous scrotal temperature could induce a significant increase in the embryonic mortality rate. As these changes were apparent on day 4 of heating, an effect must have occurred on sperm stored in the epididymis.
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http://dx.doi.org/10.1530/jrf.0.0940337DOI Listing
March 1992

Concomitant stimulation by vasopressin of biliary and perfusate calcium fluxes in the perfused rat liver.

Biochem J 1992 Jan;281 ( Pt 2):387-92

Division of Biochemistry and Molecular Biology, School of Life Sciences, Australian National University, Canberra, A.C.T.

Changes in perfusate Ca2+ (measured with a Ca(2+)-selective electrode) and changes in bile calcium (measured by atomic absorption spectroscopy) were continuously and simultaneously monitored after infusion of (a) vasopressin, (b) glucagon and (c) both vasopressin and glucagon together to the perfused rat liver. Also monitored were perfusate glucose and oxygen concentrations and bile flow. Vasopressin induces a sharp, transient, pulse of increased bile flow and increased bile calcium within 1 min of infusion, concomitant with rapid changes in perfusate Ca2+ fluxes, glucose output and oxygen uptake. This is immediately followed by a decrease in both bile flow and bile calcium for as long as the hormone is administered. Changes induced by glucagon are a relatively slow onset of perfusate Ca2+ efflux and oxygen uptake, but rapid glucose output, and a small but significant and transient decrease in bile flow and bile calcium which, despite the continued infusion of the hormone, spontaneously and rapidly returns to normality. However, the greatest responses are observed after co-administration of both hormones. Coincident with the augmented perfusate Ca2+ fluxes (influx) seen in earlier work, there occurs within 1 min of vasopressin infusion a sharp increase in bile secretion and bile calcium greater in magnitude than that produced by vasopressin alone. Immediately thereafter bile secretion and bile calcium decline below basal values and remain there for as long as the hormones are administered. Glucagon and vasopressin therefore each have opposing effects on bile flow and bile calcium. However, the action of vasopressin is enhanced by the prior administration of glucagon. The data thus reveal features about the actions of glucagon and Ca(2+)-mobilizing hormones on bile flow and bile calcium not previously recorded and provide a novel framework around which the whole issue of hepato-biliary Ca2+ homoeostasis can be assessed in normal and diseased liver.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1130696PMC
http://dx.doi.org/10.1042/bj2810387DOI Listing
January 1992

Proline and glycine betaine in cryoprotective diluents for ram spermatozoa.

Reprod Fertil Dev 1992 ;4(1):113-8

Department of Animal Sciences, Waite Agricultural Research Institute, University of Adelaide, Glen Osmond, SA, Australia.

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http://dx.doi.org/10.1071/rd9920113DOI Listing
June 1992
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