Evidence for the role of insulin-like growth factor II (IGF-II) in the control of food intake.
Highly purified insulin-like growth factors I and II and insulin (100 ng peptide/animal) were injected intracerebroventricularly in rats and the effect on 24 hour food consumption examined. IGF-II injections resulted in a 21% decrease in food intake and 4% body weight loss over the 24 hour period following peptide administration whereas IGF-I and insulin had no effect on either parameter. Increasing the amount of IGF-II injected also increased these responses with depressions of 22, 33 and 44% occurring in rats given 33, 100 and 300 ng IGF-II respectively. In addition, tissue concentrations of IGF-II were detected and found to be differentially distributed, via radioimmunoassay, in specific regions of the brain implicated in the regulation of food intake. IGF-I was not found in these same tissue punches despite radioimmunoassay sensitivity of 6 pg.
Lauterio
T J
TJ
Metabolism Division, Washington University School of Medicine, St. Louis, MO 63110.
Marson
L
L
Daughaday
W H
WH
Baile
C A
CA
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001923:Brain Chemistry; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D005247:Feeding Behavior / Q000187:drug effects*; D007276:Injections, Intraventricular; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007335:Insulin-Like Growth Factor II / Q000008:administration & dosage / Q000032:analysis / Q000494:pharmacology*; D008297:Male; D009928:Organ Specificity; D010902:Pituitary Gland / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D013002:Somatomedins / Q000494:pharmacology*
D007328:Insulin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II