Ogunbiyi P O, Eyre P
Res Commun Chem Pathol Pharmacol. 1984 Apr;44(1):31-55.
The vasoconstrictor actions of 5-hydroxytryptamine (5-HT) were investigated in the isolated helical strips of the pulmonary artery and vein of the adult bovine and calf. Agonist-antagonist interactions were studied by pretreating the vessels with methysergide, ketanserin and phentolamine and then establishing the dose-response curves to 5-HT or noradrenaline (NA). Methysergide significantly (p less than 0.05) inhibited 5-HT-induced contractions in the vessels. Ketanserin antagonized the vasoconstrictor actions of 5-HT but inhibition was not dose-related. NA-induced contractions of the vessels from the adult bovine were non-competitively inhibited by ketanserin. Phentolamine (PH) competitively antagonized contractions induced by 5-HT and NE in the tissues. The results suggest that 1. ketanserin is a potent, competitive antagonist of 5-HT but a weak antagonist of NE and 2. 5-HT-induced contractions in the bovine pulmonary vessels are mediated via specific tryptamine receptors (5-HT2) and alpha-adrenergic receptors.
在成年牛和小牛的离体肺动脉和肺静脉螺旋条上研究了5-羟色胺（5-HT）的血管收缩作用。通过用麦角新碱、酮色林和酚妥拉明预处理血管，然后建立对5-HT或去甲肾上腺素（NA）的剂量反应曲线，研究了激动剂-拮抗剂相互作用。麦角新碱显著（p<0.05）抑制5-HT诱导的血管收缩。酮色林拮抗5-HT的血管收缩作用，但抑制作用与剂量无关。酮色林对成年牛血管由NA诱导的收缩产生非竞争性抑制。酚妥拉明（PH）竞争性拮抗5-HT和NE在组织中诱导的收缩。结果表明：1. 酮色林是5-HT的强效竞争性拮抗剂，但对NE是弱拮抗剂；2. 5-HT诱导的牛肺血管收缩是通过特异性色胺受体（5-HT2）和α-肾上腺素能受体介导的。
