育亨宾对犬基底动脉的收缩作用。
Contractile action of yohimbine in the dog basilar artery.
作者信息
Oshita M, Kigoshi S, Muramatsu I
出版信息
Blood Vessels. 1985;22(6):257-64. doi: 10.1159/000158612.
Yohimbine (10(-8) to 10(-4) M) produced a concentration-dependent contraction of the isolated dog basilar artery. The maximal amplitude of the contraction induced by yohimbine was approximately 50% of that induced by 5-hydroxytryptamine (5-HT) and twice as large as that of noradrenaline. This response to yohimbine (3 X 10(-7) M) was attenuated by 5-HT receptor antagonists such as 5-methoxygramine, methysergide and ketanserin. Phentolamine also antagonized the yohimbine response but prazosin and DG-5128 did not. The 5-HT antagonists and phentolamine produced similar inhibition of the response to 5-HT. Propranolol, atropine and diphenhydramine did not modify the contractile responses to yohimbine and 5-HT. These results suggest that the contractile response to yohimbine is mediated through 5-HT receptors. In addition to the contractile action, yohimbine at concentrations over 10(-6) M inhibited the contractile response to 5-HT. Thus, the possibility that yohimbine is a partial agonist on 5-HT receptors in the dog basilar artery has to be considered.
育亨宾（10⁻⁸至10⁻⁴M）可引起离体犬基底动脉浓度依赖性收缩。育亨宾诱导的收缩最大幅度约为5-羟色胺（5-HT）诱导幅度的50%，是去甲肾上腺素诱导幅度的两倍。5-羟色胺受体拮抗剂如5-甲氧基格拉明、麦角新碱和酮色林可减弱对育亨宾（3×10⁻⁷M）的这种反应。酚妥拉明也可拮抗育亨宾反应，但哌唑嗪和DG-5128则不能。5-羟色胺拮抗剂和酚妥拉明对5-羟色胺反应的抑制作用相似。普萘洛尔、阿托品和苯海拉明不改变对育亨宾和5-羟色胺的收缩反应。这些结果表明，对育亨宾的收缩反应是通过5-羟色胺受体介导的。除收缩作用外，浓度超过10⁻⁶M的育亨宾可抑制对5-羟色胺的收缩反应。因此，必须考虑育亨宾是犬基底动脉5-羟色胺受体部分激动剂的可能性。
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