[Mice in cages. Some relations between behavior and adrenal cortex function].

High density lipoprotein (HDL) and low density lipoprotein (LDL) are cholesterol transport particles whose plasma concentrations are directly (LDL) and inversely (HDL) correlated with risk for atherosclerosis. LDL catabolism involves cellular uptake and degradation of the entire particle by a well-characterized receptor. HDL, in contrast, selectively delivers its cholesterol, but not protein, to cells by unknown receptors. Here it is shown that the class B scavenger receptor SR-BI is an HDL receptor. SR-BI binds HDL with high affinity, is expressed primarily in liver and nonplacental steroidogenic tissues, and mediates selective cholesterol uptake by a mechanism distinct from the classic LDL receptor pathway.

Adrenal Glands↗

PubMed1996

Differential effects of endogenous and exogenous nitric oxide on the release of endothelin-1 from the intact perfused rat adrenal gland in situ.

Studies using an inhibitor of nitric oxide (NO) synthesis have suggested that endogenous NO may have a role in regulating endothelin release. We investigated the effect of endogenous and exogenous nitric oxide (NO) on the release of irET-1. L-NAME stimulated, but L-arginine inhibited irET-1 release. Perfusing sodium nitroprusside (SNP), however, did not inhibit irET-1 secretion. CyclicGMP, the second messenger for NO action, was stimulated by SNP but not by L-arginine. These data demonstrate that endogenous NO inhibits of irET-1, in a manner which is independent of cGMP, and suggest that this action may contribute to the vasodilatory effect of NO.

Adrenal Glands↗