The glucose-6-phosphatase/glucokinase ratio in the liver of obese-diabetic subjects.
The study of G6Pase and GK activities in human liver (needle biopsies) in overnight fasted obese NIDDM patients has shown that, while G6Pase was unchanged, GK was higher (+ 55%, P less than 0.05) than in control subjects. Consequently, the G6Pase/GK ratio (which roughly reflects hepatic glucose production) was significantly reduced (-36%) in the obese diabetic group, due to more GK activity (glucose uptake). This contrasts with the activity in IDDM and nonobese NIDDM patients (where the G6Pase/GK ratio is elevated and normal, respectively) and would suggest that in the obese diabetic subjects, hepatic glucose production is not a major factor contributing to the maintenance of hyperglycemia in the overnight fasting state (leaving peripheral insulin resistance as the major cause of hyperglycemia).
Belfiore
F
F
Chair of Pathophysiology of Metabolism, Ospedale Garibaldi, Catania, Italy.
Romeo
F
F
Iannello
S
S
Salamone
C
C
D000328:Adult; D003920:Diabetes Mellitus / Q000201:enzymology*; D003924:Diabetes Mellitus, Type 2 / Q000201:enzymology*; D005260:Female; D005941:Glucokinase / Q000378:metabolism*; D005952:Glucose-6-Phosphatase / Q000378:metabolism*; D006593:Hexokinase / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D009765:Obesity
D006593:Hexokinase; D005941:Glucokinase; D005952:Glucose-6-Phosphatase