Béa M L, Ghaleh B, Giudicelli J F, Berdeaux A
Département de Pharmacologie, Faculté de Médecine Paris-Sud, Le Kremlin-Bicêtre, France.
Br J Pharmacol. 1994 Apr;111(4):981-2. doi: 10.1111/j.1476-5381.1994.tb14839.x.
This study was designed to test the role of endothelium and the L-arginine/NO pathway in the relaxation of canine large coronary arteries to the beta-adrenoceptor agonist, isoprenaline. Relaxation of left circumflex (LCX) and left anterior descending (LAD) coronary arteries were measured in organ baths after contraction with the thromboxane analogue, U46619, either in absence or in presence of endothelium and in LCX arteries after pretreatment with NG-nitro-L-arginine-methyl-ester (L-NAME). LAD arteries with and without endothelium relaxed identically to isoprenaline but their maximal relaxation was smaller than corresponding LCX arteries with endothelium. A slight but non significant difference was observed in LCX arteries with endothelium as compared to rings without endothelium or pretreated with L-NAME. No difference was observed in the relaxation of LCX arteries to forskolin in arteries with or without endothelium. These results suggest that endothelium is not essential and that NO is not directly involved in the relaxation of large coronary arteries induced by isoprenaline.
本研究旨在测试内皮细胞以及L-精氨酸/一氧化氮（NO）途径在犬大冠状动脉对β-肾上腺素能受体激动剂异丙肾上腺素舒张反应中的作用。在用血栓素类似物U46619收缩后，于离体器官浴槽中测量左旋支（LCX）和左前降支（LAD）冠状动脉的舒张情况，分别检测有无内皮细胞时以及用NG-硝基-L-精氨酸甲酯（L-NAME）预处理后LCX动脉的舒张情况。有无内皮细胞的LAD动脉对异丙肾上腺素的舒张反应相同，但它们的最大舒张程度小于相应有内皮细胞的LCX动脉。与无内皮细胞或用L-NAME预处理的血管环相比，有内皮细胞的LCX动脉存在轻微但无统计学意义的差异。有无内皮细胞的LCX动脉对福斯高林的舒张反应无差异。这些结果表明，内皮细胞并非必需，且NO不直接参与异丙肾上腺素诱导的大冠状动脉舒张。
