In vivo uptake and metabolism of low density lipoprotein in the guinea pig adrenal.
Adrenal uptake and metabolism of circulating low density lipoprotein (LDL) was examined in female guinea pigs. [H3]LDL was prepared by exchange labeling with [H3]cholesteryl linoleate. After its injection plasma [H3]sterol ester concentration declined rapidly. This decline was slower in those animals pretreated with dexamethasone than in untreated controls. At 120 min after [H3]LDL administration [H3]-cholesteryl esters and [H3]cholesterol were detected in the adrenal gland. The levels of both radioactive and radioinert esters were lower in animals given dexamethasone. In contrast no difference in radioactive or radioinert cholesterol concentration was evident. In a second experiment [H3]LDL was prepared by reconstitution of the LDL-core with [H3]cholesteryl linoleate. After administration its disappearance from the circulation was similar to that observed in the first experiment. Other organs also took up [H3]LDL including the liver and kidney. Free and esterified [H3]cholesterol concentrations were greater in the liver than in the adrenal gland at 120 min after injection. The results from these two experiments were interpreted to mean that th adrenal cortex is capable of taking up LDL and metabolizing its cholesteryl esters. Uptake may be stimulated by ACTH.
D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002784:Cholesterol / Q000097:blood; D002788:Cholesterol Esters / Q000097:blood; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D006854:Hydrocortisone / Q000097:blood; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male
D002788:Cholesterol Esters; D008077:Lipoproteins, LDL; D003907:Dexamethasone; D002784:Cholesterol; D006854:Hydrocortisone