Cholesterol arachidonate as a prostaglandin precursor in adrenocortical cells.
Rat adrenocortical cells were incubated with labeled arachidonate, and the radioactivity in unesterified fatty acids was reduced by washing with 2% albumin solutions. These cells were then incubated for two hours in the absence and presence of 7.1 x 10(-10)M ACTH. During subsequent incubation of prelabeled cells with ACTH, both the mass and radioactivity of arachidonate in adrenocortical cholesteryl esters was depleted to the same extent (30--32%). The released arachidonate was in part incorporated into phospholipids, and there was also a significant increase in unesterified arachidonic acid. During this period, there was also increased incorporation of arachidonate into labeled prostaglandins. Of this increase, 92% by isotope analysis, and 88% by radioimmunoassay techniques was attributable to prostaglandins of the E pathway. These data demonstrate that prostaglandin E synthesis is specifically increased during ACTH stimulation of rat adrenocortical cells and suggest that a major source of the arachidonate substrate for this synthesis is derived from hormone-dependent hydrolysis of cortical cholesteryl esters.
D000302:Adrenal Cortex / Q000166:cytology / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism*; D050356:Lipid Metabolism; D011453:Prostaglandins / Q000096:biosynthesis*; D011863:Radioimmunoassay; D051381:Rats
D001095:Arachidonic Acids; D011453:Prostaglandins; D000324:Adrenocorticotropic Hormone; D002784:Cholesterol