Lipoprotein-mediated regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and cholesteryl ester metabolism in the adrenal gland of the rat.

The role of high density lipoproteins in the biodistribution of two radioiodinated probes in the rat

“…Moreover, this decrease in circulating lipoproteins could also cause an increase in the number of HDL receptors in target tissues, which is consistent with the known regulation of adrenal activity (Brown et al, 198 1;Balasubramaniam et al, 1977b;Pittman et al, 1982). Both or either one of these possibilities could account for the dramatic increase in adrenal uptake of '251-CO-HDL in the hypolipidemic animals.…”

“…The dramatic uptake of '251-CO-HDL into the adrenal and, to a lesser extent, the ovaries is consistent with the results obtained in Balasubramaniam et al, 1977bBalasubramaniam et al, , 1976 importance of high and low density lipoproteins in Gwynne and Hess, 1978;Strauss et al, 1982) the reeulation of cholesterol svnthesis in the adrenal ROLE OF HDL IN DRUG BIODISTRIBUTION…”

“…In man, LDL are the major carrier of plasma cholesterol to extrahepatic tissues. However, studies with rats indicate that the adrenal cortex relies mainly upon circulating high density lipoproteins (HDL) as the source of cholesterol (Anderson and Dietschy, 1978;Carr et al, 1980;Faust et al, 1977;Balasubramaniam et al, 1977b).…”

Kinetics and mechanism of phosphatidylcholine and cholesterol exchange between single bilayer vesicles and bovine serum high-density lipoprotein

“…In contrast to the latter type of interactions between membranes and lipoproteins, which are not mediated by transfer proteins or cell membrane receptors, some peripheral tissues have specific receptors for low density lipoproteins. The interaction between the receptors and low density lipoproteins triggers the internalization of the entire lipoprotein and the subsequent events of lipoprotein hydrolysis, depression of cholesterol synthesis, and stimulation of cholesteryl ester synthesis (Goldstein & Brown, 1974;Balasubramaniam et al, 1977). Similar specific receptors have not been found for high density lipoproteins with the possible exception of rat liver cells (Drevon et al, 1977).…”

Simvastatin treatment aggravates the glucocorticoid insufficiency associated with hypocholesterolemia in mice

“…Several lines of evidence have suggested that adrenal de novo cholesterol synthesis does not contribute to the generation of the steroidogenic cholesterol pool under normolipidemic conditions. More specifically, studies in rats have shown that activity of the HMG-CoA reductase, the rate-limiting enzyme in de novo cholesterol synthesis, within the adrenals is relatively low as long as cholesterol can be obtained from lipoproteins in the plasma compartment [4]. In addition, little to no activity of HMG-CoA reductase can be detected in adrenals of wild-type mice [3].…”