Interaction between growth hormone and insulin in the regulation of lipoprotein metabolism

action between growth hormone and insulin in the regulation of lipoprotein metabolism in the rat. Am J Physiol Endocri-nol Metab 283: E1023–E1031, 2002. First published July 30, 2002; 10.1152/ajpendo.00260.2002.—The importance of insu-lin for the in vivo effects of growth hormone (GH) on lipid and lipoprotein metabolism was investigated by examining the effects of GH treatment of hypophysectomized (Hx) female rats with and without concomitant insulin treatment. Hy-pophysectomy-induced changes of HDL, apolipoprotein (apo)E, LDL, and apoB levels were normalized by GH treat-ment but not affected by insulin treatment. The hepatic triglyceride secretion rate was lower in Hx rats than in normal rats and increased by GH treatment. This effect of GH was blunted by insulin treatment. The triglyceride con-tent in the liver changed in parallel with the changes i