血管腔内、外给L-硝基精氨酸对电刺激所致肠系膜动脉灌注压的影响

目的比较血管腔内、外给硝基精氨酸对电刺激所致大鼠肠系膜动脉灌注压的影响。方法应用灌流离体血管方法，测定肠系膜动脉灌注压变化。结果电刺激引起大鼠肠系膜动脉灌注压明显升高，血管腔内、外给ＮＯ合酶抑制剂Ｌ－硝基精氨酸（Ｌ－ＮＡ）均明显增强上述灌注压升高反应，此１９９８－０１－０８收稿，１９９８－０３－２０修回＊河北省自然科学基金资助课题，Ｎｏ３９４２５１作者简介：张建新，男，４４岁，医学博士（日本），研究员，药理研究室副主任增强作用可被ＮＯ供体－Ｌ精氨酸阻断。血管腔内、外给Ｌ－ＮＡ不改变基础灌注压而且对外源性去甲肾上腺素的作用也无明显影响。结论静脉注射ＮＯ合酶抑制剂不仅可直接作用于内皮，而且也可透过内皮、平滑肌作用于外周血管神经末梢，减少ＮＯ合成进而增强肾上腺素能神经刺激所致的收缩血管反应。

Modification by extraluminal and intraluminal N G nitro L arginine of neurally induced pressor response of mesenteric artery segments

AIM To observe the effects of extraluminal and intraluminal N G nitro L arginine ( L NA) on electrical stimulation induced pressor response in perfused rat mesenteric artery segments. METHODS The perfusion pressure was measured via a pressure transducer placed upstream of the artery segment from rat on an inkwriting oscillograph.RESULTS In isolated, perfused rat mesenteric artery segments, intraluminal infused L NA potentiated the pressor response to transmural electrical stimulation, as did extraluminal L NA. L arginine reversed the potentiating effect of L NA. Intraluminal L NA did not increase the basal pressure and the response to norepinephrine. The arterial endothelium and media do not seem to interfere with the access of intraluminal L NA to perivascular nerve terminals. CONCLUSION Intravenously applied NO synthase inhibitors are not necessarily considered to act solely on the endothelium but also apparently affect nerves distributed in the adventitia, and interfere with vasodilator, nitroxidergic nerve function, thus potentiating the respose to adrenergic nerve stimulation.