Corticosterone effect on insulin receptor number and kinase activity in chicken muscle and liver.
The effects of chronic corticosterone treatment (6 mg/kg/day) on insulin sensitivity and on liver and muscle insulin receptors were examined in 5-week-old chickens. The hypoglycemic effect of exogenous insulin was completely abolished within 2 weeks of treatment, suggesting a corticosterone-induced insulin resistance. Hepatic insulin receptor numbers were slightly reduced (P < 0.001) after 2 weeks of treatment. After 1 or 2 weeks, corticosterone treatment significantly reduced liver insulin receptor kinase activity toward the artificial substrate poly(Glu4,Tyr1). Muscle insulin receptor kinase activity was also significantly decreased after 1 week of treatment but this effect was accounted for by a decrease in basal activity. Therefore the corticosterone-induced insulin resistance is accounted for, at least in part, by altered hepatic receptor numbers and kinase activity. The impairment of muscle development involves postreceptor defects.
INRA, Station de Recherches Avicoles, Nouzilly, France.
M
M
Taouis
M
M
Derouet
B
B
Chevalier
J
J
Simon
D000273:Adipose Tissue / Q000187:drug effects; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D002645:Chickens; D003345:Corticosterone / Q000494:pharmacology*; D004435:Eating / Q000187:drug effects; D007328:Insulin / Q000097:blood; D008099:Liver / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011972:Receptor, Insulin / Q000187:drug effects*
D001786:Blood Glucose; D007328:Insulin; D011505:Protein-Tyrosine Kinases; D011972:Receptor, Insulin; D003345:Corticosterone