Characterization of glucose uptake by cultured rat podocytes.
The nonmetabolizable glucose analogue [(3)H]-2-deoxy-D-glucose ((3)H-2DG) was used to study glucose transport in cultured rat podocytes. Intracellular accumulation of (3)H-2DG was linear up to 20 min and was inhibited by cytochalasin B (80% inhibition) and by phlorizin (20% inhibition). Pretreatment with insulin stimulated the (3)H-2DG uptake 1.5-fold. A Hill analysis of the rate of glucose transport yielded a V(max) value of approximately 10 mM and S(0.5)of 7.8 mM. The value h = 1.0 for a Hill coefficient confirmed that glucose uptake exhibited a Michaelis-Menten kinetics. Transporters GLUT2 and GLUT4 were expressed in over 90% podocytes. Of the GLUT2- and GLUT4-expressing cells, approximately one-fourth expressed the membrane-bound fraction. We conclude that cultured rat podocytes possess a differentiated glucose transport system consisting chiefly of facilitative GLUT2 and GLUT4 transporters. It seems likely that a sodium-dependent glucose cotransporter may also be present in these cells.
Lewko
Barbara
B
Department of Immunopathology, Medical University of Gdansk, Gdansk, Poland. blew@amedec.amg.gda.pl
Bryl
Ewa
E
Witkowski
Jacek M
JM
Latawiec
Elzbieta
E
Gołos
Magdalena
M
Endlich
Nicole
N
Hähnel
Brunhilde
B
Koksch
Claudia
C
Angielski
Stefan
S
Kriz
Wilhelm
W
Stepinski
Jan
J
D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003847:Deoxyglucose / Q000494:pharmacology; D005260:Female; D005947:Glucose / Q000378:metabolism*; D051273:Glucose Transporter Type 2 / Q000378:metabolism; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D050199:Podocytes / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D000963:Antimetabolites; D051273:Glucose Transporter Type 2; D051275:Glucose Transporter Type 4; D007004:Hypoglycemic Agents; D007328:Insulin; D003847:Deoxyglucose; D005947:Glucose