Recent experimental studies showed an important role of endothelium derived relaxing factor for cavernous smooth muscle relaxation. Since nitr ic oxide seems to account for the biological actions of endothelium derived relaxing factor, a study was done to examine a possible role of the nitric oxide donor linsidomine chlorhydrate (SIN-1) i n the treatment of erectile dysfunction. To determine a ...

The discovery of prostacyclin and its endothelial origin established the idea of endothelium-derived vasoactive eicosanoids and led to the realization that endothelial cells were a source of autacoids that regulate vascular tone.1,2 In 1980, Furchgott and Zawadzki3 described endothelium-derived relaxing factor (EDRF) and presented evidence that EDRF was a lipoxygenase metabolite of arachidonic ...

The early vascular effects of photodynamic therapy (PDT) include transient vasoconstriction and platelet aggregation. Since endothelium-derived relaxing factor (EDRF) is a potent vasodilator and inhibitor of platelet aggregation, we questioned whether PDT impairs the production of EDRF. To study this possible effect of PDT, endothelium-dependent relaxations of thoracic aortas obtained from male...

Asymmetric dimethylarginine (ADMA), which inhibits NO synthase, is inactivated by N(G),N(G)-dimethylarginine dimethylaminohydrolase (DDAH). We tested whether DDAH-1 or -2 regulates serum ADMA (S(ADMA)) and/or endothelium-derived relaxing factor (EDRF)/NO. Small inhibitory (si)RNAs targeting DDAH-1 or -2, or an siRNA control were given intravenously to rats. After 72 hours, EDRF/NO was assessed ...

The relation between endothelin and acetylcholine (ACh) was examined and compared in aortas from Wistar-Kyoto (WKY) rats and from stroke-prone spontaneously hypertensive rats (SHRSP). The relaxation produced by ACh in an endothelin-induced contraction was less in aortas from WKY rats than in those from SHRSP. In aortas from WKY rats but not in those from SHRSP, the contraction produced by endot...

The possible role of thyroid hormones in the Nitric Oxide (NO)-mediated response to sexual stimulation, and on prostaglandin E1 (PGE1) and Sildenafil in the treatment of erectile dysfunction was investigated using the corpus cavernosum of the New Zealand rabbit animal model. The parameters studied were penile erection monitored as contractile force of the erectile tissue, sperm count and motili...

BACKGROUND AND PURPOSE The goal of this study was to determine whether release of endothelium-derived relaxing factor (EDRF) from carotid artery in response to acetylcholine is altered by aging. METHODS Responses were examined in arteries from Wistar rats 6 to 8 months old (young rats), 24 to 26 months old (old rats), and 30 to 32 months old (very old rats). We used a bioassay technique to me...

The blocker of receptor-mediated calcium entry SK&F 96365 was used to evaluate the contribution of calcium influx to the formation of biologically active endothelial prostanoids and endothelium-derived relaxing factor (EDRF). SK&F 96365 inhibited histamine-stimulated calcium entry into human umbilical vein endothelial cells but not its discharge from intracellular stores as determined spectrofl...

Endothelium-dependent relaxation is mediated by the release from vascular endothelium of an endothelium-derived relaxing factor (EDRF). It is not clear what role arachidonic acid has in this process. Inhibition of phospholipase A2, and diacylglycerol lipase in cultured bovine aortic endothelial cells caused a marked reduction in agonist-induced arachidonic acid release from membrane phospholipi...

To elucidate the effects of endothelium-derived relaxing factor (EDRF) released from vascular endothelial cells (ECs) on handling of intracellular calcium ion (Ca2+i) in ECs themselves and vascular smooth muscle cells (VSMCs), we measured the Ca2+i by two-dimensional digital image analysis of fura-2-loaded ECs and VSMCs in tissue culture. In isoculture of one cell type, adenosine triphosphate (...