Boe J, Simonsson B G
Eur J Respir Dis. 1980 Aug;61(4):195-202.
We tested the in vitro contractility of 88 segmental pulmonary arteries from 46 patients undergoing thoracic surgery. The vascular strips, taken from macroscopically healthy lung tissue, were devoid of spontaneous adrenergic tone. Cumulative dose-response curves with epinephrine and norepinephrine showed graded contraction. There was no significant difference between the two substances concerning mean maximal tension, threshold doses, ED50 or concentrations causing maximal contraction. Alpha-receptor blocking agents, phenoxybenzamine and indoramine, showed an inhibition of the contraction induced with both epinephrine and norepinephrine. Epinephrine in higher doses caused a dual response: contraction followed by relaxation. The latter was blocked by propranolol. Both isoproterenol and theophylline relaxed contracted vessels to some extent. Relaxation induced by isoproterenol could be blocked by propranolol. "Selective" beta2-stimulants such as terbutaline or salbutamol induced no relaxation. The results suggest the presence of alpha-receptors mediating constriction and possibly beta1-receptors mediating relaxation in human segmental arteries.
我们检测了46例接受胸外科手术患者的88条肺段动脉的体外收缩性。取自宏观上健康肺组织的血管条无自发肾上腺素能张力。肾上腺素和去甲肾上腺素的累积剂量-反应曲线显示出分级收缩。两种物质在平均最大张力、阈剂量、半数有效剂量（ED50）或引起最大收缩的浓度方面无显著差异。α受体阻断剂酚苄明和吲哚拉明可抑制肾上腺素和去甲肾上腺素诱导的收缩。高剂量肾上腺素引起双相反应：先收缩后舒张。后者可被普萘洛尔阻断。异丙肾上腺素和茶碱均可使收缩的血管有一定程度的舒张。异丙肾上腺素诱导的舒张可被普萘洛尔阻断。“选择性”β2激动剂如特布他林或沙丁胺醇未诱导舒张。结果提示在人肺段动脉中存在介导收缩的α受体以及可能介导舒张的β1受体。
