Glucose entry into rat mesangial cells is mediated by both Na(+)-coupled and facilitative transporters.

Diabetologia 1995 Mar;38(3):291-7

Department of Biological Chemistry, Harvard Medical School, Boston, Massachusetts, USA.

Since previous studies from our laboratory have demonstrated that increased glucose consumption by cultured rat mesangial cells is accompanied by an accelerated production of type IV and type VI collagen, we have now examined the manner by which glucose is transported into these cells. A progressive stimulation of glucose uptake by the mesangial cells was observed with increasing concentrations of NaCl so that at 145 mmol/l about twice as much glucose entered the cells as in its absence (substituted by choline chloride). Moreover, since phlorizin inhibited the NaCl-promoted uptake of glucose and this salt was found to increase the accumulation of alpha-methylglucoside in a manner which could not be duplicated by KCl or mannitol, both Na(+)-coupled and facilitative glucose transporters appeared to be present in the cells. Km values of 1.93 mmol/l and 1.36 mmol/l were determined for the co-transport and facilitated transport pathways, respectively, with their Vmax being 29.5 and 18.0 nmol.mg protein-1.h-1. Both uptake activities were found to be down-regulated by exposure of the cells to high glucose and furthermore the Na(+)-dependent transport could no longer be detected after about 12 passages of the cells. Hybridization of mesangial cell mRNA with cDNA probes revealed transcripts for the Na+/glucose co-transporter as well as GLUT1 and to a lesser extent GLUT4.(ABSTRACT TRUNCATED AT 250 WORDS)

Download full-text PDF

Source
http://dx.doi.org/10.1007/BF00400633DOI Listing
March 1995

Publication Analysis

Top Keywords

mesangial cells
12
cells
8
na+-coupled facilitative
8
glucose
8
rat mesangial
8
cells values
4
mannitol na+-coupled
4
appeared cells
4
transporters appeared
4
glucose transporters
4
facilitative glucose
4
values 193
4
mmol/l 136
4
co-transport facilitated
4
facilitated transport
4
transport pathways
4
determined co-transport
4
mmol/l determined
4
kcl mannitol
4
136 mmol/l
4

References

(Supplied by CrossRef)

P Kimmelstiel et al.
Am J Clin Pathol 1962

K Iidaka et al.
Lab Invest 1968

SM Mauer et al.
J Clin Invest 1984

RG Spiro et al.
1988

PS Mohan et al.
Diabetes 1990

T Danne et al.
Diabetes 1993

M Wakisaka et al.
Diabetes 1994

GI Bell et al.
Diabetes Care 1990

B Sactor et al.
Kidney Int 1989

M Mueckler et al.
J Diab Comp 1993

RG Spiro et al.
J Biol Chem 1967

Similar Publications