Ethanol causes decrements in airway excretion of endogenous nitric oxide in humans.

Ethanol has previously been demonstrated to inhibit excretion of endogenous nitric oxide (NO) in exhaled air from experimental animals. The aim of the present study was to elucidate if this effect also occurs in human subjects. Healthy volunteers ingested ethanol (0.

Direct demonstration of NO formation in vivo from organic nitrites and nitrates, and correlation to effects on blood pressure and to in vitro effects.

Previous studies, utilizing nitric oxide synthase inhibitors and nitric oxide application, indicate that nitric oxide has the capacity to modulate contractile responses in pulmonary vessels. In the present study, in vitro effects of organic nitrates/nitrites were compared with their in vivo ability to generate nitric oxide and their effects on blood pressure. Glyceryl trinitrate, ethyl nitrite, isobutyl nitrate, isobutyl nitrite, isoamyl nitrite and butyl nitrite inhibited contractions in response to nerve stimulation in guinea pig pulmonary artery and vas deferens.

Modulation of neuroeffector transmission in guinea-pig pulmonary artery and vas deferens by exogenous nitric oxide.

Blockade of nitric oxide (NO) synthesis enhances contractile responses to transmural nerve stimulation in guinea-pig pulmonary artery, indicating neuromodulation by endogenous nitric oxide. In the present study, neuromodulatory effects of exogenous NO were examined in guinea-pig pulmonary artery and vas deferens. Application of NO as acid nitrite, to the guinea-pig pulmonary artery, inhibited the contractile response to transmural nerve stimulation as well as contractions to exogenous noradrenaline.

Modulation of neuroeffector transmission in the guinea pig pulmonary artery by endogenous nitric oxide.

The influence of endogenous nitric oxide (NO) on neuroeffector transmission in segments of guinea pig pulmonary artery was analyzed by application of NG-monomethyl-L-arginine (L-NMMA). L-NMMA enhanced contractile responses to nerve stimulation and this enhancement was counteracted by L-arginine. The enhancement remained after removal of the endothelium.

Endothelin modulation of neuroeffector transmission in smooth muscle.

In a series of muscle preparations, the peptides endothelin-1 (ET-1) and endothelin-3 (ET-3) were investigated for effects on basal muscle tone, responses to transmural nerve stimulation, and release of [3H]norepinephrine or [3H]acetylcholine. ET-1 and ET-3 contracted rat vas deferens and guinea pig ileum, ET-1 being the most potent. In the guinea pig taenia coli, ET-1 induced a relaxation whereas ET-3 was almost without relaxing effect.