Liver lipase-like activity in human and hamster adrenocortical tissue

Human adrenocortical tissue was found to contain a lipase activity that could be measured in vitro in the presence of 0.6 M NaCl at pH 8.5. The lipase was largely (80%) inhibitable by an antibody raised against heparin-releasable liver lipase. The activity of the lipase per gram tissue wet weighty was threefold higher in hyperplastic than in normal adrenocortical tissue (165 microunits vs 50 microunits). No or very low lipase activity was found in adrenocortical tumors. When, employing the same assay system, lipase activity was measured in the adrenal gland of golden hamsters a very low activity, compared with rat adrenal gland,--was found (13 mU)g w.w. vs 225 mU/g w.w.). Since liver lipase may be involved in the uptake of cholesterol from serum high density lipoproteins by the liver, the presence of a similar lipase in adrenal glands suggests that this tissue can also take up cholesterol by a lipase-mediated mechanism in human and rat. In human adrenocortical carcinomas and in the normal hamster gland such a mechanism seems to be absent.