Decreased hepatic glycogen content and accelerated response to starvation in rats with carbon tetrachloride-induced cirrhosis.
Glucose homeostasis and fatty acid metabolism are abnormal in patients with cirrhosis. To assess the metabolic response to starvation in an animal model of cirrhosis, glycogen and fuel metabolism were characterized in rats with CCl4-induced cirrhosis studied 2 wk after 10 weekly doses of CCl4. Plasma concentrations of glucose and beta-hydroxybutyrate were not different between fed CCl4-treated and control rats, but plasma nonesterified fatty acid concentrations were higher in cirrhotic animals (0.25 +/- 0.01 vs. 0.39 +/- 0.04 mmol/L; p less than 0.05). After 12 hr of starvation, the plasma nonesterified fatty acid concentration had reached 0.58 +/- 0.04 mmol/L in CCl4-treated rats, compared with 0.38 +/- 0.04 mmol/L in control rats (p less than 0.05). The redistribution of the hepatic carnitine pool toward acylcarnitines, which is characteristic of starvation, was complete after fasting for 12 hr in the CCl4-treated rats, compared with the 24 hr required in control rats. In fed cirrhotic rats, liver glycogen content per gram liver was decreased by 64% compared with control rats (30.0 +/- 5.1 vs. 10.8 +/- 1.1 mg/gm liver wet wt; p less than 0.05). After 12-hr fasting, hepatic glycogen content had fallen to 14.3 +/- 3.9 and 4.8 +/- 0.4 mg/gm liver wet wt (p less than 0.05) in control and cirrhotic animals, respectively. To further characterize the status of glycogen metabolism in cirrhotic livers, activities of glycogen synthase and glycogen phosphorylase were determined. Hepatic active and total glycogen phosphorylase activities normalized to hepatocellular content were unaffected by CCl4 treatment, whereas total glycogen synthase activity was increased by 45%.(ABSTRACT TRUNCATED AT 250 WORDS)
Krahenbuhl
S
S
Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106.
Weber
F L
FL
Brass
E P
EP
D000818:Animals; D002251:Carbon Tetrachloride; D002331:Carnitine / Q000378:metabolism; D004734:Energy Metabolism; D006003:Glycogen / Q000378:metabolism*; D006006:Glycogen Synthase / Q000378:metabolism; D006706:Homeostasis; D008099:Liver / Q000378:metabolism*; D008106:Liver Cirrhosis, Experimental / Q000139:chemically induced / Q000378:metabolism*; D008297:Male; D006005:Phosphorylases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013217:Starvation / Q000378:metabolism*
D006003:Glycogen; D002251:Carbon Tetrachloride; D006005:Phosphorylases; D006006:Glycogen Synthase; D002331:Carnitine