Suppression of the hepatic glucose-6-phosphatase system in diabetic rats by vanadate.
The effect of oral administration of vanadate on the transport and hydrolytic components of the glucose-6-phosphatase system in liver homogenates from streptozotocin-induced diabetic rats was examined. Blood glucose was normalized in diabetic rats receiving 0.8 mg/ml vanadate but a catabolic effect was observed on body and liver weight. Significant changes in the coupled reactions for glucose-6-phosphate transport by T1 and hydrolysis by the enzyme were noted. The dramatic elevation in the maximal velocity of glucose-6-phosphatase brought about by diabetes was suppressed by vanadate administration. As a result, the relationship between T1 and the enzyme returned to the normal range. It is concluded that the suppression of glucose-6-phosphate hydrolysis in diabetes may contribute to the normalizing effect of vanadate on blood glucose.
Schulz
L O
LO
Department of Health Sciences, University of Wisconsin-Milwaukee.
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D005952:Glucose-6-Phosphatase / Q000037:antagonists & inhibitors*; D006868:Hydrolysis; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014638:Vanadates / Q000494:pharmacology*
D001786:Blood Glucose; D014638:Vanadates; D005952:Glucose-6-Phosphatase