Salt resistant lipase activity in human adrenal gland is increased in Cushing's disease

Abstract

Salt resistant lipase (also designated hepatic lipase) is present in normal human adrenal cortex at activity levels of about 1 mU g-1 tissue wet weight. In hyperplastic adrenocortical tissue from four patients with Cushing's disease the salt resistant lipase activity was found to be about 5-fold higher than this value. The activity of salt resistant lipase in postheparin plasma was elevated in two of the patients, indicating that the high enzyme activity in adrenal cortex may originate from the liver. Lipoprotein lipase activity in postheparin plasma was clearly depressed in all patients with Cushing's disease and was associated with moderate hypertriglyceridaemia and slightly lowered HDL cholesterol levels. Thus high ACTH and/or corticosteroid levels appear to affect lipoprotein metabolism by a number of mechanisms.

Cloning, expression, and promoter analysis of hepatic lipase derived from human hyperplastic adrenals

“…Here, we show for the first time that full-length HL mRNA is expressed in the hyperplastic adrenals of patients with Cushing's disease. These adrenals are activated by increased pituitary secretion of ACTH, and contain elevated levels of HL activity (30,31). We corroborated these findings by promoter-reporter assays using the human adrenocortical NCI-H295R cell line.…”

“…In HL-null mice, the ACTH-induced increase in plasma corticosterone levels was attenuated, suggesting that adrenal HL is important for steroidogenesis (34). In patients with Cushing's disease, adrenal HL activity is severalfold higher than in controls (30,31), and the daily cortisol production is increased in parallel (30). Taken together, these observations strongly suggest that adrenal HL has an important role in cholesterol supply for steroid production (34).…”

ACTH 1‐24 decreases hepatic lipase activities and low density lipoprotein concentrations in healthy men

“…We have previously shown that patients with pituitary Cushing's disease (endogenous ACTH overproduction) exhibit a fivefold increase in HL activity of adrenal tissue [6]. The present experiment was undertaken to determine the way in which ACTH affects HL activity in human liver.…”

Lipoprotein lipase in guinea-pig adrenals: activity, mRNA, immunolocalization and regulation by ACTH

“…LPL is the enzyme that hydrolyses the bulk of triacylglycerols carried in larger apolipoprotein Bcontaining lipoproteins such as chylomicra and very low density lipoprotein. It has been reported that H-type lipase activity is increased in rat adrenals after ACTH treatment and in humans with Cushing's disease (Jansen, Schoonderwoerd, Baggen & de Greef, 1983;Berg, Hansson & Nilsson-Ehle, 1990). -type lipase is present mainly in the liver (Semenkovich, Chen, Wims et al 1989), but in the rat the enzyme protein has also been demonstrated in adrenals and ovaries (Jansen & de Greef, 1981).…”