Wiest E, Trach V, Dämmgen J
Department of Biological Research, Dr. Karl Thomae GmbH, Biberach, FRG.
Basic Res Cardiol. 1989 Sep-Oct;84(5):469-78. doi: 10.1007/BF01908199.
Studies of the role of the endothelium in coronary resistance vessels are limited to investigations of endothelium-derived relaxing factor mediated effects using various blocking agents. Endothelium removal as an alternative approach, is restricted to larger epicardial vessels. This study demonstrates the effect of endothelial damage by saponin on coronary resistance vessels remaining intact within the heart. In an isolated perfused guinea pig heart a saponin-containing solution (50 micrograms/ml) was infused over 2 min to damage specifically the endothelium. Increases of coronary flow in response to carbachol, histamine, and serotonin were completely blocked and reversed to decreases. Angiotensin-I-induced vasoconstriction was attenuated, whereas angiotensin-II-induced vasoconstriction remained unchanged. Vasodilatory response to sodium-nitroprusside was not attenuated by saponin-treatment. In contrast inhibition of endothelium derived relaxing factor by gossypol inhibited carbachol-induced vasodilation but did not result in vasoconstriction. Electron microscopic examination ensured that while the endothelium was destroyed by saponin-treatment the vascular smooth muscle was left intact. Our data indicate a regulating influence of the vascular endothelium on coronary resistance vessels which can be totally eliminated by saponin-treatment.
关于内皮细胞在冠状动脉阻力血管中作用的研究，仅限于使用各种阻断剂对内皮源性舒张因子介导的效应进行研究。作为一种替代方法，去除内皮细胞仅限于较大的心外膜血管。本研究证明了皂苷对心脏内完整的冠状动脉阻力血管内皮损伤的影响。在离体灌流豚鼠心脏中，在2分钟内注入含皂苷的溶液（50微克/毫升）以特异性损伤内皮细胞。对卡巴胆碱、组胺和5-羟色胺的冠状动脉血流增加完全被阻断并转为减少。血管紧张素I诱导的血管收缩减弱，而血管紧张素II诱导的血管收缩保持不变。对硝普钠的血管舒张反应不受皂苷处理的影响。相比之下，棉酚抑制内皮源性舒张因子可抑制卡巴胆碱诱导的血管舒张，但不会导致血管收缩。电子显微镜检查证实，虽然皂苷处理破坏了内皮细胞，但血管平滑肌保持完整。我们的数据表明血管内皮对冠状动脉阻力血管有调节作用，而皂苷处理可完全消除这种作用。
