Medina P, Chuan P, Noguera R, Vila J M, Aldasoro M, Lluch S
Department of Physiology, University of Valencia, Spain.
J Androl. 1996 Nov-Dec;17(6):733-9.
The present study was designed to investigate general morphology and the response of human deferential artery to constrictor and dilator substances with special emphasis on endothelium-dependent responses. Human deferential artery segments were obtained from patients undergoing radical cystectomy (n = 7), suprapubic prostatectomy (n = 6), or radical prostatectomy (n = 6). Light microscopy revealed that human deferential artery is of muscular type, and fluorescence microscopy showed a dense adrenergic innervation. Paired rings, one normal and the other de-endothelialized by gentle rubbing, were mounted for isometric recording of tension in organ baths. Vasopressin, endothelin, serotonin, and potassium chloride induced endothelium-independent contractions, whereas norepinephrine and electrical field stimulation caused frequency-dependent contractions that were of greater magnitude in arteries denuded of endothelium. In precontracted arterial rings, acetylcholine and substance P induced endothelium-dependent relaxations. In contrast, papaverine and sodium nitroprusside caused concentration-dependent relaxations that were similar in the presence and in the absence of endothelium. NG-nitro-L-arginine methyl ester (10(-4) M), an inhibitor of nitric oxide synthase, potentiated the responses to norepinephrine in artery rings with endothelium, nearly abolished the acetylcholine-induced relaxation, and attenuated the relaxation induced by substance P. incubation with methylene blue (10(-5) M), an inhibitor of guanylate cyclase, completely prevented the relaxation induced by acetylcholine in arteries with endothelium. The results of this study indicate that the human deferential artery has a dense adrenergic innervation and marked ability to contract or relax in response to different agonists. Some of these responses are in part endothelium dependent and mediated through release of nitric oxide. These morphological and pharmacological observations could play an important role in regulating flow or pressure of blood that arrives to the vas deferens.
本研究旨在调查人类输精管动脉的一般形态以及其对收缩剂和扩张剂的反应，特别关注内皮依赖性反应。从接受根治性膀胱切除术（n = 7）、耻骨上前列腺切除术（n = 6）或根治性前列腺切除术（n = 6）的患者中获取人类输精管动脉段。光学显微镜显示人类输精管动脉为肌性动脉，荧光显微镜显示有密集的肾上腺素能神经支配。将一对血管环，一个正常，另一个通过轻轻摩擦去除内皮，安装在器官浴槽中进行等长张力记录。血管加压素、内皮素、5-羟色胺和氯化钾诱导非内皮依赖性收缩，而去甲肾上腺素和电场刺激引起频率依赖性收缩，在去除内皮的动脉中收缩幅度更大。在预收缩的动脉环中，乙酰胆碱和P物质诱导内皮依赖性舒张。相反，罂粟碱和硝普钠引起浓度依赖性舒张，在内皮存在和不存在的情况下相似。一氧化氮合酶抑制剂NG-硝基-L-精氨酸甲酯（10(-4) M）增强了有内皮的动脉环对去甲肾上腺素的反应，几乎消除了乙酰胆碱诱导的舒张，并减弱了P物质诱导的舒张。用鸟苷酸环化酶抑制剂亚甲蓝（10(-5) M）孵育，完全阻止了有内皮的动脉中乙酰胆碱诱导的舒张。本研究结果表明，人类输精管动脉有密集的肾上腺素能神经支配，并且对不同激动剂有明显的收缩或舒张能力。其中一些反应部分是内皮依赖性的，并通过一氧化氮的释放介导。这些形态学和药理学观察结果可能在调节到达输精管的血流或压力方面发挥重要作用。
