Effect of chronic undernutrition on hepatocyte insulin receptors in rats.
The effect of moderate chronic undernutrition on insulin receptors was studied in male rats, pair-fed 60% of the daily food intake of ad libitum-fed littermates, for 8 weeks. Body weights of undernourished rats were consistently found to be 35% to 40% less than control littermates, with no period of growth arrest at any point in the 8-week study. The binding-displacement curves of labeled insulin to hepatocyte receptors in the two groups in the presence of unlabeled insulin were significantly different (P = .0258 after repeated measures ANOVA). Significantly lower binding was observed in hepatocytes from the undernourished group (P less than .01) at all unlabeled insulin concentrations less than 20 nmol/L. In the absence of any unlabeled insulin, specific binding was reduced from 8.8% +/- 0.7%, (mean +/- SE) in controls, to 7.4% +/- 0.3% in undernourished rats (P less than .01). Half-maximal specific hormone binding to hepatocytes was achieved at a free insulin concentration of 362 nmol/L in the control group, compared with 447 nmol/L in the undernourished group, reflecting an increase of approximately 20%. The hypoglycemic response to intravenous insulin (0.1 U/kg body weight) was tested in a parallel experiment involving seven paired littermate rats, and found to be significantly impaired in the undernourished group (P = .0041 by repeated measures ANOVA).(ABSTRACT TRUNCATED AT 250 WORDS)
Rao
R H
RH
Department of Medicine, University of Pittsburgh School of Medicine, PA.
Betschart
J M
JM
Virji
M A
MA
D000704:Analysis of Variance; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002908:Chronic Disease; D006128:Growth; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009748:Nutrition Disorders / Q000378:metabolism* / Q000503:physiopathology; D051381:Rats; D011919:Rats, Inbred Strains; D011972:Receptor, Insulin / Q000378:metabolism*
D001786:Blood Glucose; D007328:Insulin; D011972:Receptor, Insulin