Insulin-like action of chromate on glucose transport in isolated rat adipocytes.
The effects of chromium compounds on 3-O-methylglucose (3-O-MG) transport were studied in isolated rat adipocytes. Sodium chromate significantly stimulated 3-O-MG uptake into adipocytes in a dose-dependent manner without altering the equilibrium space of 3-O-MG in adipocytes. The stimulatory effect reached the maximum at 300 microM, and the effect was 60-70% of the maximal insulin effect that was obtained with 20 nM insulin. The chromate concentration achieving a half-maximal effect was estimated at 50 microM. The effect of the combination of 1 mM chromate and 20 nM insulin was equipotent to that of 20 nM insulin alone, which showed that these two effects were not additive. The stimulatory effects of 1 mM chromate and 20 nM insulin were entirely abolished in adipocytes deprived of ATP, which indicated that these effects were completely ATP-dependent. Judging from experiments using various chromium compounds, CrO4(2-) was responsible for the insulinomimetic action. These results indicate that the action of CrO4(2-) is exerted through a mechanism analogous to that of insulin action, and that CrO4(2-) is a novel and useful tool for studying issues involved in insulin actions.
Goto
Y
Y
Department of Pediatrics, Ehime University School of Medicine, Japan.
Kida
K
K
D019325:3-O-Methylglucose; D000255:Adenosine Triphosphate / Q000172:deficiency; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002840:Chromates / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004822:Epididymis; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology*; D007668:Kidney; D008297:Male; D008757:Methylglucosides / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000187:drug effects; D011190:Potassium Cyanide / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D017670:Sodium Compounds / Q000494:pharmacology*
D002840:Chromates; D007328:Insulin; D008757:Methylglucosides; D009004:Monosaccharide Transport Proteins; D017670:Sodium Compounds; D019325:3-O-Methylglucose; C028982:sodium chromate(VI); D000255:Adenosine Triphosphate; D011190:Potassium Cyanide