Increased rates of hepatic cholesterogenesis and fatty acid synthesis in septic rats in vivo: evidence for the possible involvement of insulin

Abstract

1. Sepsis induced by caecal ligation and puncture increased the rates of hepatic cholesterogenesis and fatty acid synthesis in vivo compared with sham-operated rats. These changes were accompanied by higher concentrations of lactate and pyruvate in blood and liver and an increase in plasma insulin. 2. The total activity of hydroxymethylglutarylcoenzyme A (HMG-CoA) reductase (EC 1.1.1.88) in liver was increased by sepsis, but there was no significant change in the expressed activity. Short-term insulin deficiency (induced by mannoheptulose or streptozotocin) decreased the rates of cholesterogenesis and fatty acid synthesis in livers of septic rats but did not alter the expressed/total activity of HMG-CoA reductase. 3. It is concluded that the increased rate of hepatic cholesterogenesis in septic rats is in part a result of the higher plasma insulin, the hormone acting to maintain the total activity of HMG-CoA reductase and to stimulate a step before the formation of HMG-CoA. 4. These changes may contribute to the hypertriacyl-glycerolaemia associated with sepsis.