Coronary microvascular response to endothelin is dependent on vessel diameter and route of administration.
Coronary microvascular response to endothelin is dependent on vessel diameter and route of administration.
复制标题
冠状动脉微血管对内皮素的反应取决于血管直径和给药途径。
DOI：
10.1152/ajpheart.1992.263.3.h703
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Marcus,ML
中科院分区：
文献类型：
--
作者：
Lamping,KG;Clothier,JL;Eastham,CL;Marcus,ML
Endothelin is a 21-amino acid peptide originally isolated from vascular endothelial cells. In the present study, we examined the effect of topical and intracoronary administration of endothelin-1 on the coronary microcirculation and the effect of inhibition of cyclooxygenase on the microvascular response to intracoronary endothelin. In anesthetized dogs (n = 39), the coronary microcirculation was visualized using stroboscopic epi-illumination synchronized to the cardiac cycle. Topical application of endothelin [(5 x 10(-9) to 10(-8) M] constricted all arteries and arterioles with the degree of constriction inversely related to vessel size. Coronary veins and venules did not constrict to endothelin. Topical application of EDTA (10 mg/ml) reversed the constriction to endothelin in arterioles of all sizes. In contrast, intracoronary administration of endothelin (10(-8) to 10(-7) M) produced dilation of small arterioles (less than 130 microns) and no response of large arterioles (greater than 130 microns). The response of small arterioles to intracoronary endothelin was not altered by inhibition of cyclooxygenase with indomethacin (5 mg/kg); however, large arterioles constricted. Thus the coronary microvascular response to endothelin is dependent on the route of administration. Constriction of arteries and arterioles of all sizes to endothelin is dependent on extracellular calcium. Vasodilator prostaglandins may be released in response to intracoronary administration of endothelin predominantly in larger vessels. Thus the differential response to endothelin with topical and intracoronary administration may reflect a diffusional barrier of the endothelium or release of endothelium-derived relaxing factor and prostaglandins in response to endothelin.
