BACKGROUND Healthy middle-aged postmenopausal women have higher endothelium-dependent dilation and lower vasoconstrictor activity of endothelin-1 than men. Whether these sex-specific differences extend to patients with cardiovascular risk factors has not been investigated. The current study aimed to determine whether, in patients with cardiovascular risk factors, sex-specific differences exist ...

Aging has been reported to cause impotence, the mechanism of which is unknown. Therefore, we investigated the effect of aging on electrical stimulation-induced neurogenic, carbachol-induced, endothelium-dependent, and sodium nitroprusside-induced cGMP-dependent relaxant responses of rabbit corporal smooth muscle. Male New Zealand white rabbits were divided into young (4 months), intermediate (8...

There is considerable evidence that endothelium-dependent nitric oxide (NO)-mediated vasodilatation in response to acetylcholine is impaired in essential hypertension, whereas the endothelium-independent response to sodium nitroprusside is normal. More limited data have suggested that there is also reduced vasoconstriction in response to N(G)-monomethyl-L-arginine (L-NMMA), a competitive inhibi...

Local warming of skin induces vasodilation by unknown mechanisms. To test whether nitric oxide (NO) is involved, we examined effects of NO synthase (NOS) inhibition with NG-nitro-L-arginine methyl ester (L-NAME) on vasodilation induced by local warming of skin in six subjects. Two adjacent sites on the forearm were instrumented with intradermal microdialysis probes for delivery of L-NAME and so...

1. It has been shown in animals that substance P as well as acetylcholine releases endothelium-derived nitric oxide and evokes vasodilatation and that ATP-induced vasodilatation is partially mediated by nitric oxide. The aim of this study was to examine whether vasodilator effects of substance P and ATP are mediated by nitric oxide in humans. 2. In healthy volunteers (n = 35), we measured forea...

The acute haemodynamic effects of oral pirbuterol (a beta-agonist) were contrasted with those of sodium nitroprusside, a vasodilator, in six patients with hypoxic chronic bronchitis and emphysema. Sodium nitroprusside (1-5 mg/kg intravenously) reduced mean pulmonary arterial pressure and total pulmonary vascular resistance significantly (p less than 0.01) without change in cardiac output or rig...

Skin microvascular responses to iontophoresis of acetylcholine, an endothelium-dependent vasodilator, and sodium nitroprusside, an endothelium-independent vasodilator, were measured using a laser Doppler imager whose software controlled iontophoretic current delivery in an integrated fashion. A novel feature involved monitoring voltage across the iontophoresis chambers during current applicatio...

Nitric oxide (NO*) is a gaseous mediator synthesized by nitric oxide synthases. NO* is involved in the modulation of inflammation, but its role in airway inflammation remains controversial. We investigated the role of NO* in the synthesis of the chemokines interleukin-8 and monocyte chemotactic protein-1, and of intercellular adhesion molecule-1 by human airway epithelial cells. normal human br...

The changes in plasma level of alpha-atrial natriuretic polypeptide (alpha-ANP) and the relaxing responses to exogenous alpha-ANP of strips of rat aorta pretreated with methoxamine were examined at one, four and eight weeks after myocardial infarction induced by left coronary ligation. Responses to a beta-adrenergic stimulant, isoprenaline, and sodium nitroprusside of the vessel pretreated with...

Carbon monoxide (CO) is an endogenous dilator in the newborn cerebral microcirculation. Other dilators include prostanoids and nitric oxide (NO), and interactions among the systems are likely. Experiments on anesthetized piglets with cranial windows address the hypothesis that CO-induced dilation of pial arterioles involves interaction with the prostanoid and NO systems. Topical application of ...