Regulation of c-fos expression in adipose and muscle tissue of diabetic rats.
Insulin treatment of control rats demonstrated a marked 8-fold transient increase (15 min) in c-fos mRNA in white adipose tissue, which returns to basal levels by 5 h. Similarly, insulin treatment resulted in a rapid 9-fold increase in cardiac muscle c-fos mRNA, which also returned to control values by 1 h. By contrast, insulin treatment resulted in only a small increase in c-jun mRNA levels in both adipose tissue and cardiac muscle. Similarly, the expression of c-jun mRNA was only slightly responsive to insulin in these tissues from streptozocin-induced insulin-deficient diabetic rats. However, insulin treatment of insulin-deficient diabetic rats resulted in a prolonged increase in c-fos message levels in adipose tissue without any significant change in the time course of c-fos mRNA induction/repression in cardiac muscle. These data demonstrate that in contrast to c-jun, c-fos is transiently increased in both cardiac muscle and adipose tissue by insulin treatment. Furthermore, transrepression of the c-fos gene is specifically attenuated in adipose tissue of insulin-deficient diabetic rats, but not in cardiac muscle.
Olson
A L
AL
Department of Physiology and Biophysics, University of Iowa College of Medicine, Iowa City 52242.
Pessin
J E
JE
D000273:Adipose Tissue / Q000378:metabolism / Q000503:physiopathology*; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000235:genetics*; D004822:Epididymis; D005786:Gene Expression Regulation; D016762:Genes, fos; D016758:Genes, jun; D007328:Insulin / Q000494:pharmacology; D008297:Male; D009132:Muscles / Q000378:metabolism / Q000503:physiopathology*; D009206:Myocardium / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D013997:Time Factors
D007328:Insulin; D012333:RNA, Messenger