Peroxovanadate but not vanadate exerts insulin-like effects in human adipocytes.
Vanadate and peroxovanadate were recently reported to exert maximal or even supramaximal (peroxovanadate) insulin-like effects in rat adipocytes. To evaluate the response in human cells, isolated human adipocytes were exposed to insulin or various concentrations of vanadate (0-10 mmol/l) or peroxovanadate (0-5 mmol/l). Neither vanadate nor peroxovanadate affected 125I-insulin binding and insulin sensitivity. Vanadate exerted no apparent effect on 14C-U-glucose uptake, whereas 0.1 mmol/l peroxovanadate exerted a full insulin-like response (p < 0.001). No additive response was observed by combining either vanadate or peroxovanadate with insulin. Peroxovanadate at 0.1 mmol/l was as effective as insulin in inhibiting isoproterenol-stimulated lipolysis. Neither peroxovanadate nor insulin-inhibited lipolysis stimulated by N6-monobutyryl-cAMP, an analogue which is not hydrolysed by the cAMP-phosphodiesterase. It is concluded that peroxovanadate, but not vanadate, elicits a full insulin-like response in human adipocytes.
Lönnroth
P
P
Department of Medicine, University of Göteborg, Sweden.
Eriksson
J W
JW
Posner
B I
BI
Smith
U
U
D000273:Adipose Tissue / Q000166:cytology* / Q000187:drug effects; D001692:Biological Transport / Q000502:physiology; D001706:Biopsy; D002250:Carbon Radioisotopes; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000493:pharmacokinetics; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology; D008066:Lipolysis / Q000187:drug effects; D014638:Vanadates / Q000494:pharmacology*
D002250:Carbon Radioisotopes; D007328:Insulin; C069276:peroxovanadate; D014638:Vanadates; D005947:Glucose; D007545:Isoproterenol