When fresh rabbit aorta is incubated with plasma, prostacyclin, a potent inhibitor of platelet aggregation, is normally released. Plasma obtained from 2 patients with systemic lupus erythematosus (SLE) inhibited prostacyclin activity, while plasma from 22 other patients with SLE and 40 normal control subjects showed normal activity. Absence of prostacyclin activity did not appear to correlate w...

BACKGROUND Myocardial revascularization surgery has used several vessels as coronary grafts including internal mammary and radial arteries which have a better prognosis than saphenous vein. Their long-term patency has been associated with the release of endothelium vasodilator and anti-aggregating products such as prostacyclin. Diabetes induces endothelial dysfunction and a high number of diabe...

Prostacyclin is a short-lived metabolite of arachidonic acid that is produced by several cells in the lung and prominently by endothelial cells. It increases intracellular cAMP levels activating downstream signaling thus regulating vascular mesenchymal cell functions. The alveolar wall contains a rich capillary network as well as a population of mesenchymal cells, i.e., fibroblasts. The current...

Epoprostenol sodium (prostacyclin) administered intravenously is considered the standard for assessing the ability of the pulmonary circulation to vasodilate. At present, epoprostenol sodium is an investigational drug that has limited availability. In contrast, acetylcholine, also a pulmonary vasodilator, is readily available. Therefore, we assessed the feasibility of using acetylcholine as an ...

Labeled and unlabeled prostacyclin and 6-keto-PGF1, were infused into healthy volunteers; urine was chromatographed on different systems including high pressure liquid chromatography. The peaks obtained by the latter method were derivatized to the methoxime methyl ester trimethyl silyl ether and analyzed by gasliquid chromatography-mass spectrometry. After infusion of prostacyclin the follo...

Prostacyclin is the principal product of prostaglandin (PG) endoperoxide (PGH,) metabolism in rabbit mesenteric arteries and veins, as assessed by synthesis of 6-oxo-PGFla. Formation of PGE,, PGD,, PGFfc, and C17-hydroxyacid of PGH, (HHT) were also detected but arose probably from non-enzymic decomposition of PGH,. The effects of prostacyclin (PGI,), 6-oxo-PGFla and PGE, on sympathetic nerre fu...

OBJECTIVES Progestogens have been poorly studied concerning their roles in endothelial physiology. Prostanoids are vasoactive compounds, such as thromboxane A2, a potent vasoconstrictor, and prostacyclin, a vasodilator. We examined the effects of two progestogens used clinically, progesterone and medroxyprogesterone acetate, on thromboxane A2 production by cultured human umbilical vein endothel...

Indapamide, a nonthiazide diuretic, exhibits direct vasodilator action as well as natriuretic and diuretic effects. Although calcium antagonist-like activity has been addressed so far, the mechanisms for vasodilator effect are still uncertain. To understand the wide range of indapamide actions, we examined the effects of indapamide on the vascular eicosanoid generation and investigated its mech...

We aimed at evaluating the relative contribution of cyclooxygenase (COX) -1 and COX-2 to the synthesis of prostacyclin in endothelial cells under static conditions in the presence or absence of exogenous arachidonic acid and/or altered intracellular redox balance. Selective inhibitors of either COX-1 (SC560 and FR122047) or COX-2 (SC236) concentration dependently (1-300 nM) reduced basal and in...

One major unresolved issue in muscle blood flow regulation is that of the role of circulating versus interstitial vasodilatory compounds. The present study determined adenosine-induced formation of NO and prostacyclin in the human muscle interstitium versus in femoral venous plasma to elucidate the interaction and importance of these vasodilators in the 2 compartments. To this end, we performed...