Effects of Growth Hormone on Leucine Metabolism in Adipose Tissuein Vitro1

Abstract

Paired samples of rat epididymal adipose tissue were incubated in bicarbonate buffer in the presence of glucose and dl-leucine-2-C¹⁴. Bovine growth hormone added to the incubation medium at a concentration of 1 μg/ml doubled the conversion of leucine-C¹⁴ to fatty acids in adipose tissue from hypophysectomized rats. Porcine, ovine and human growth hormone preparations had similar effects. However, no such stimulation of leucine metabolism was seen when adipose tissue from normal rats was used. Corticotropin, thyrotropin and oxytocin had no effect on leucine metabolism, but ovine prolactin in high doses (25–100 μg) was found to stimulate the conversion of leucine to fatty acids. Growth hormone also increased the uptake of leucine from the incubation medium but did not influence the oxidation of leucine to CO₂.