Acute actions of insulin-like growth factor II on glucose metabolism in adult rats.
The metabolic potency of recombinant human insulin-like growth factor II was studied in anaesthetized adult rats by obtaining dose-response curves for the hypoglycaemic action and for the stimulation of glucose metabolism during euglycaemic clamping. Compared to insulin, about 50 times higher doses of insulin-like growth factor II were required to result in identical in vivo responses, with half-maximally effective serum concentrations for the stimulation of glucose disposal during clamp studies of about 0.8 and 50 pmol/ml, respectively. A similar difference in potency was observed for the dose-dependent stimulatory actions on glucose metabolism in individual target tissues. Half-maximally effective serum concentrations in the range of 0.8 to 3.0 pmol/ml for insulin and of 40 to 70 pmol/ml for insulin-like growth factor II were seen to be required for 2-deoxyglucose uptake, glycogen formation in skeletal muscle and lipogenesis in epididymal fat. Maximal responses were identical with both peptides. These data suggest that in vivo acute metabolic actions of insulin-like growth factor II on carbohydrate metabolism occurred through insulin receptors.
Stümpel
F
F
Department of Medicine, Georg-August-Universität, Göttingen, FRG.
Hartmann
H
H
D000818:Animals; D002250:Carbon Radioisotopes; D003847:Deoxyglucose / Q000378:metabolism / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D004822:Epididymis / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism; D007003:Hypoglycemia / Q000378:metabolism; D007275:Injections, Intravenous; D007335:Insulin-Like Growth Factor II / Q000008:administration & dosage / Q000494:pharmacology*; D050356:Lipid Metabolism; D008297:Male; D009132:Muscles / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014316:Tritium
D002250:Carbon Radioisotopes; D014316:Tritium; D007335:Insulin-Like Growth Factor II; D006003:Glycogen; D003847:Deoxyglucose; D005947:Glucose