Auch-Schwelk W, Vanhoutte P M
Baylor College of Medicine, Houston, Texas.
Blood Press. 1992 May;1(1):45-9. doi: 10.3109/08037059209065123.
Contractions to endothelin-1 in aortas of the spontaneously hypertensive rats (SHR) were compared with those of normotensive controls (WKY); rings with and without endothelium were studied in organ chambers. Contractions to endothelin were smaller in aortas of SHR compared to WKY, whether the endothelium was present or not. The presence of a functional endothelium reduced contractions to the peptide in both strains. Endothelium-dependent relaxations to acetylcholine and endothelium-independent relaxations to nitric oxide were observed in rings from both strains during contraction with endothelin. Indomethacin reduced the contractions to endothelin in the aorta from SHR with endothelium, but not in those without endothelium; it did not significantly affect endothelin-induced contractions in rings of WKY with or without endothelium. These experiments demonstrate that contractions of the vascular smooth muscle to endothelin are reduced in the aorta of the SHR. The basal and stimulated release of endothelium-derived relaxing factor inhibits contractions to endothelin in the aorta from both strains. The inhibitor of cyclooxygenase indomethacin does not prevent the response of the vascular smooth muscle to endothelin; however, endothelin may stimulate the release of an indomethacin-sensitive endothelium-derived contracting factor in the SHR aorta.
将自发性高血压大鼠（SHR）主动脉对内皮素-1的收缩反应与正常血压对照大鼠（WKY）进行比较；在器官浴槽中研究有内皮和无内皮的血管环。无论有无内皮，SHR主动脉对内皮素的收缩反应均小于WKY。功能性内皮的存在使两种品系血管环对该肽的收缩反应降低。在用内皮素收缩期间，在两种品系的血管环中均观察到对乙酰胆碱的内皮依赖性舒张和对一氧化氮的非内皮依赖性舒张。吲哚美辛可降低有内皮的SHR主动脉对内皮素的收缩反应，但对无内皮的主动脉无此作用；它对有或无内皮的WKY血管环中内皮素诱导的收缩反应均无显著影响。这些实验表明，SHR主动脉中血管平滑肌对内皮素的收缩反应降低。内皮衍生舒张因子的基础释放和刺激释放均抑制两种品系主动脉对内皮素的收缩反应。环氧合酶抑制剂吲哚美辛不能阻止血管平滑肌对内皮素的反应；然而，内皮素可能刺激SHR主动脉中一种对吲哚美辛敏感的内皮衍生收缩因子的释放。
