Differential sensitivity to endothelin in canine arteries and veins.
Differential sensitivity to endothelin in canine arteries and veins.
复制标题
犬动脉和静脉对内皮素的敏感性不同。
DOI：
10.1152/ajpheart.1989.257.4.h1127
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Vanhoutte,PM
中科院分区：
文献类型：
--
作者：
Miller,VM;Komori,K;BurnettJr,JC;Vanhoutte,PM
实验旨在比较静脉和动脉平滑肌对内皮素的敏感性，并确定内皮源性舒张因子和一氧化氮是否能抑制对肽的收缩。将犬冠状动脉左前降支、股动脉、肠系膜动脉、股静脉和隐静脉环（有内皮和无内皮）悬挂，以测量等长力。在吲哚美辛，酚妥拉明和普萘洛尔的存在下，内皮素在所有环中引起浓度依赖性张力增加。静脉比动脉对肽更敏感。内皮素使隐静脉和肠系膜动脉的平滑肌去极化;静脉中的去极化阈值浓度（10（-10）M）比动脉中的去极化阈值浓度（10（-8）M）低约100倍。去除内皮仅增强静脉平滑肌对内皮素的敏感性。然而，无论是乙酰胆碱或钙离子载体A23187在动脉中的内皮细胞的刺激迅速抑制的最大张力开发的肽。在无内皮的动脉和静脉中，一氧化氮抑制内皮素的收缩;动脉中的抑制作用大于静脉。提示静脉平滑肌对内皮素的敏感性高于动脉平滑肌。在这两种血管中，内皮源性舒张因子可以抑制肽的收缩。
Experiments were designed to compare the sensitivity of venous and arterial smooth muscle to endothelin and to determine whether contractions to the peptide could be inhibited by endothelium-derived relaxing factor and nitric oxide. Rings of canine left anterior descending coronary, femoral, and mesenteric arteries and femoral and saphenous veins with and without endothelium were suspended for measurement of isometric force. In the presence of indomethacin, phentolamine, and propranolol, endothelin initiated concentration-dependent increases in tension in all rings. The veins were more sensitive to the peptide than were the arteries. Endothelin depolarized the smooth muscle of the saphenous veins and mesenteric arteries; the threshold concentration for depolarization was approximately 100 times lower in the veins (10(-10) M) than in the arteries (10(-8) M). Removal of the endothelium enhanced the sensitivity only of venous smooth muscle to endothelin. However, stimulation of the endothelium in the arteries with either acetylcholine or the calcium ionophore A23187 rapidly inhibited the maximal tension developed to the peptide. Nitric oxide inhibited contractions to endothelin in arteries and veins without endothelium; the inhibition was greater in the arteries than in the veins. These results indicate that venous smooth muscle is more sensitive than arterial smooth muscle to endothelin. In both blood vessels, endothelium-derived relaxing factor(s) can inhibit contractions to the peptide.