Differential effects of blood insulin levels on microsomal enzyme activities from hepatic and extrahepatic tissues of male rats.
Microsomal glutathione S-transferase, UDP-glucuronyl transferase, and aniline hydroxylase activities were determined in liver, renal cortex, and small intestine of control, streptozotocin-diabetic, alloxan-diabetic, and untreated insulin-injected male Wistar rats. Renal microsomal glutathione S-transferase activity showed a direct linear relationship with insulin blood levels, in agreement with our previous report on cytosolic glutathione S-transferase. This result suggests a possible regulatory mechanism of insulin that needs to be further examined. The hepatic microsomal UDP-glucuronyl transferase was only decreased in streptozotocin-diabetic rats and was not restored by insulin treatment. Intestinal UDP-glucuronyl transferase exhibited an opposite response in streptozotocin-treated animals that was not normalized by the administration of insulin. Hepatic aniline hydroxylase showed the same behaviour as intestinal UDP-glucuronyl transferase. These results suggest that streptozotocin and (or) its metabolites have a direct effect on hepatic and intestinal UDP-glucuronyl transferase activity and on hepatic aniline hydroxylase activity. On the other hand, insulin regulation of enzyme activity varies from one organ to another.
Carnovale
C E
CE
Instituto de Fisiologia Experimental, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Argentina.
Catania
V A
VA
Monti
J A
JA
Carrillo
M C
MC
D000815:Aniline Hydroxylase / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007328:Insulin / Q000097:blood*; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D007328:Insulin; D003577:Cytochrome P-450 Enzyme System; D000815:Aniline Hydroxylase; D014453:Glucuronosyltransferase; D005982:Glutathione Transferase