缺氧和内皮介导的绵羊回旋支冠状动脉环药理反应性变化

Hypoxia- and endothelium-mediated changes in the pharmacological responsiveness of circumflex coronary artery rings from the sheep.

作者信息

Kwan Y W, Wadsworth R M, Kane K A

机构信息

Department of Physiology and Pharmacology, University of Strathclyde, Glasgow.

出版信息

Br J Pharmacol. 1989 Apr;96(4):857-63. doi: 10.1111/j.1476-5381.1989.tb11895.x.

DOI:10.1111/j.1476-5381.1989.tb11895.x

PMID:2472846

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1854449/

Abstract

The role(s) of the endothelium in modulating the responsiveness of isolated circumflex coronary artery rings (o.d. = 2.0-2.5 mm and o.d. = 0.6-1.3 mm) from sheep was investigated under oxygenated and hypoxic conditions. 2. Removal of the endothelium abolished the contraction produced by lowering the PO2 from 620 to 8 mmHg (either under optimal resting tension or precontracted by 40 mM KCl). In denuded artery rings sudden hypoxia caused relaxation. 3. Under oxygenated conditions, removal of the endothelium augmented the vasoconstrictor effects of U46619, 5-hydroxytryptamine (5-HT) and K+. In the denuded artery rings, hypoxia abolished the contractile effects of U46619 and reduced the contractile effects of 5-HT and K+. 4. Under oxygenated conditions, the vasorelaxant effect of adenosine was depressed by removal of the endothelium. In endothelium-denuded preparations, the small relaxant effect of adenosine remaining was greatly potentiated. 5. Haemolysate (1 microliter ml-1) caused an endothelium-dependent contraction under oxygenated conditions. The hypoxic contraction observed in the artery ring under resting tension was significantly potentiated by haemolysate (1 microliter ml-1). Haemolysate 1 microliter ml-1 had no effect on the denuded artery rings under hypoxic conditions. 6. Haemolysate (1 microliter ml-1) potentiated the vasoconstrictor effects of U46619 (0.5 microM), 5-HT (1 microM) and K+ (24 mM) under oxygenated conditions. 7. These results indicate that endothelium profoundly modifies the effect of hypoxia on the responsiveness of sheep isolated left circumflex coronary artery rings.

摘要

研究了内皮在氧合和缺氧条件下对绵羊离体左旋冠状动脉环（外径=2.0 - 2.5毫米和外径=0.6 - 1.3毫米）反应性的调节作用。2. 去除内皮可消除因将PO₂从620毫米汞柱降至8毫米汞柱所产生的收缩（无论是在最佳静息张力下还是预先用40毫摩尔氯化钾预收缩）。在去内皮的动脉环中，突然缺氧会导致舒张。3. 在氧合条件下，去除内皮会增强U46619、5 - 羟色胺（5 - HT）和钾离子的血管收缩作用。在去内皮的动脉环中，缺氧消除了U46619的收缩作用并降低了5 - HT和钾离子的收缩作用。4. 在氧合条件下，去除内皮会抑制腺苷的血管舒张作用。在去内皮的制剂中，剩余的腺苷的小舒张作用会大大增强。5. 溶血产物（1微升/毫升）在氧合条件下引起内皮依赖性收缩。在静息张力下动脉环中观察到的缺氧收缩被溶血产物（1微升/毫升）显著增强。1微升/毫升的溶血产物在缺氧条件下对去内皮的动脉环没有影响。6. 溶血产物（1微升/毫升）在氧合条件下增强了U46619（0.5微摩尔）、5 - HT（1微摩尔）和钾离子（24毫摩尔）的血管收缩作用。7. 这些结果表明，内皮深刻改变了缺氧对绵羊离体左旋冠状动脉环反应性的影响。