BACKGROUND Cigarette smoking is highly pathogenic to the vasculature. In smokers, the biosynthesis of both thromboxane (Tx) A2 and prostacyclin is increased. We hypothesized that the excess in prostacyclin biosynthesis in smokers was derived from the inducible cyclooxygenase-2 (COX-2). We further hypothesized that if the overproduction of prostacyclin in smokers were restraining platelet activa...

Cyclooxygenase (COX)-2 is among the endothelial genes upregulated by uniform laminar shear stress (LSS), characteristically associated with atherosclerotic lesion-protected areas. We have addressed whether the induction of COX-2-dependent prostanoids in endothelial cells by LSS plays a role in restraining endothelial tumor necrosis factor (TNF)-alpha generation, a proatherogenic cytokine, throu...

OBJECTIVE Elevated pulmonary vascular resistance and transpulmonary gradient are predictors of increased perioperative mortality in patients undergoing orthotopic heart transplantation. Sodium nitroprusside and prostacyclin PGI2 are routinely used to assess the reversibility of pulmonary vascular resistance and transpulmonary gradient in heart transplant candidates, but their use is limited by ...

BACKGROUND Pregnancy increases the risk of morbidity and mortality in sickle cell disease. We previously showed pregnant women with sickle cell disease to have a relatively low plasma renin concentration in late pregnancy, associated with a lack of the expected plasma volume expansion. We hypothesized this to be due to increased systemic vascular resistance through an imbalance between the vaso...

Prostacyclin is a potent vasodilator and inhibitor of platelet aggregation and plays an important role in maintenance of vascular homeostasis. Aspirin irreversibly inactivates prostacyclin synthetase by acetylating the enzyme. Recovery of the enzyme following inactivation by aspirin was studied in rat aorta smooth muscle cells in tissue culture. Confluent cultures superfused with [14C]arachidon...

It has been shown previously that serotonin stimulates the production of prostacyclin by bovine aortic smooth muscle cells in culture, via 5-HT2 receptors (Coughlin SR, Moskowitz MA, Antoniades HN, Levine L. Proc Natl Acad Sci USA 1981;78:7134-7138). These cells express a synthetic phenotype, whereas the majority of the smooth muscle cells in the media from adult arteries are in a contractile s...

BACKGROUND Prostacyclin (prostaglandin I(2)) is a strong vasodilator that inhibits the growth of vascular smooth muscle cells and is also the most potent endogenous inhibitor of platelet aggregation. Therefore, it has been considered to play an important roles in cardiovascular disease. On the basis of the hypothesis that variations of the prostacyclin synthase gene may also play an important r...

Background—Prostacyclin (prostaglandin I2) is a strong vasodilator that inhibits the growth of vascular smooth muscle cells and is also the most potent endogenous inhibitor of platelet aggregation. Therefore, it has been considered to play an important roles in cardiovascular disease. On the basis of the hypothesis that variations of the prostacyclin synthase gene may also play an important rol...

Chronic estrogen treatment increases endothelial vasodilator function in cerebral arteries. Endothelial nitric oxide (NO) synthase (eNOS) is a primary target of the hormone, but other endothelial factors may be modulated as well. In light of possible interactions between NO and prostaglandins, we tested the hypothesis that estrogen treatment increases prostanoid-mediated dilation using NOS-defi...

OBJECTIVE In endothelial cells, cyclooxygenase-1 (COX-1) and COX-2 both contribute to prostacyclin production. Recent findings suggest that COX-2 contributes significantly to systemic prostacyclin synthesis in humans; whether COX-2 inhibition is related to an increased cardiovascular risk is undergoing debate. HDLs have been shown to increase prostacyclin synthesis, thus in the present study we...