Wu S, Zhou M, Zhu J
Department of Physiology, Shanghai Tiedao University Medical College.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 1997 Aug;13(3):238-41.
The influence of endothelium-derived relaxing factor (EDRF) on the vasoconstrictor effect of phenylephrine on rings of rat aorta was studied in this paper. Rings of rat aorta, with or without endothelium, were suspended in organ chambers for the measurement of contractive force and contractive speed. All experiments were performed in the presence of indomethacin (10 mumol/L) to prevent the production of vasoactive prostanoids. When the preparations with intact endothelium were treated with methylene blue (10 mumol/L), an inhibitor of the target enzyme of EDRF, or NG-nitro-L-arginine (30 mumol/L), an inhibitor of EDRF formation, dose-contractive force curves of phenylephrine shifted to left: the EC30 value decreased 5-fold and the maximal response ratios were 1.6 +/- 0.4 and 1.6 +/- 0.5 (n = 8) respectively. These results were similar to those observed after mechanical removal of the endothelium: a 3-fold decrease in the EC30 value and the maximal response ratio was 1.0 +/- 0.2 (n = 8), The latter results may be related to a little EDRF produced by vascular smooth muscle. Our results suggest that the vasoconstrictive effect induced by phenylephrine may also be regulated by EDRF production from vascular endothelium and smooth muscle.
本文研究了内皮源性舒张因子（EDRF）对去氧肾上腺素作用于大鼠主动脉环的缩血管效应的影响。将有或无内皮的大鼠主动脉环悬挂于器官浴槽中，测量其收缩力和收缩速度。所有实验均在吲哚美辛（10 μmol/L）存在的情况下进行，以防止血管活性前列腺素的产生。当用EDRF靶酶抑制剂亚甲蓝（10 μmol/L）或EDRF生成抑制剂NG-硝基-L-精氨酸（30 μmol/L）处理具有完整内皮的标本时，去氧肾上腺素的剂量-收缩力曲线向左移动：EC30值降低5倍，最大反应率分别为1.6±0.4和1.6±0.5（n = 8）。这些结果与机械去除内皮后观察到的结果相似：EC30值降低3倍，最大反应率为1.0±0.2（n = 8），后者的结果可能与血管平滑肌产生的少量EDRF有关。我们的结果表明，去氧肾上腺素诱导的缩血管效应也可能受血管内皮和平滑肌产生的EDRF调节。
