Metabolic activity of cholesteryl esters in aortic smooth muscle cells is altered by prostaglandins I2 and E2.

TitleMetabolic activity of cholesteryl esters in aortic smooth muscle cells is altered by prostaglandins I2 and E2.
Publication TypeJournal Article
Year of Publication1983
AuthorsHajjar DP, Weksler BB
JournalJ Lipid Res
Volume24
Issue9
Pagination1176-85
Date Published1983 Sep
ISSN0022-2275
KeywordsAnimals, Aorta, Bucladesine, Cholesterol Esters, Dinoprostone, Epoprostenol, Female, Muscle, Smooth, Vascular, Prostaglandins E, Rabbits, Sterol Esterase, Sterol O-Acyltransferase
Abstract

Among the biochemical processes associated with the atherogenic process are increased aortic cholesteryl ester (CE) accumulation and altered prostaglandin (PG) production. The precise physiological role of PG, particularly prostacyclin (PGI2), in the control of CE metabolism in intact aortic smooth muscle cells remains to be fully elucidated. We report here that cytosolic neutral cholesteryl ester hydrolytic activity (NCEH) in intact cultured aortic smooth muscle cells is significantly increased by 75-250 nM PGI2 at the end of a 2-hr incubation period. The effect was mediated by increased intracellular cAMP levels since the effect of PGI2 on NCEH activity was abolished in the presence of an inhibitor of adenylate cyclase activity, viz., dideoxyadenosine (DDA0. Although the addition of 20-100 microM dibutyryl cAMP (Bt2cAMP) and 50-100 microM sodium arachidonate also increased NCEH activity twofold, 6-keto PGF1 alpha, PGE1, and PGE2 did not increase the activity of this enzyme. In contrast to these findings, 75-250 nM PGE2 significantly inhibited CE synthetic activity (ACAT) approximately 60%. Arachidonate or Bt2cAMP did not affect ACAT activity. This decrease in ACAT activity induced by PGE2 does not appear to be mediated by cAMP. Taken together, these findings suggest that PGI2, a well known potent vasodilator and inhibitor of platelet aggregation, and PGE2 may have an important regulatory role in aortic CE metabolism.

Alternate JournalJ Lipid Res
PubMed ID6313836
Grant ListHL-18828 / HL / NHLBI NIH HHS / United States
HL-28179 / HL / NHLBI NIH HHS / United States
Related Faculty: 
David P. Hajjar, Ph.D.

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