Effects of Cortisol and ACTH Administration on Some Aspects Of Lipid Metabolism in the Hamster. ∗

Abstract

Summary

Acetate-C¹⁴ was given intraperitoneally to hamsters which had received cortisol for 3 days or ACTH only 10 minutes previously. 1. Cortisol administration reduced the liver total lipid concentration in contrast to reports that cortisone administration to rats produces fatty livers. The contrasting response in hamsters and rats receiving similar hormones may either be attributable to species differences or depend on the amount of hormone given. 2. Cortisol administration did not lower the specific activity or incorporation of label into liver total lipid. Hepatic lipid synthesis may have compensated during the 3-day dose period for a probable, initial inhibitory effect. 3. Plasma esterified sterol concentration was elevated by cortisol treatment. The increased concentration may result from a redistribution of sterol to the vascular compartment, as found in the cortisone-treated rabbit. Plasma esterified sterol concentration was lowered by the brief ACTH treatment. This response, opposite to that produced by the prolonged cortisol treatment, indicates a direct effect, but one the basis of which is presently unknown. 4. Both ACTH and cortisol administration reduced the specific activity of plasma total lipid, an observation consistent with the lipolytic action of these hormones. 5. ACTH administration decreased the specific activity of liver total lipid. This effect could arise from the mobilization of free fatty acid and a consequent excessive generation of fatty acyl-Co A in the liver, inhibiting lipid synthesis.