摘要
浴槽内缺氧(pO_2=40mmHg,5.33kPa)可使内皮(EC)完整的猪离体肺内动脉(PA)收缩(张力升高0.86±0.09g,n=12)。去除EC后PA的缺氧收缩反应减弱(张力升高仅0.11±0.03g,n=12,P<0.01)。内皮衍生的舒张因子(EDRFs)的抑制剂美兰、棉子酚(均10^(-5)mol/L)及钙拮抗剂异搏停(10^(-5)mol/L)可显著抑制EC完整PA的缺氧性收缩反应,而消炎痛、乙胺嗪、U-60257B、U-63557A、FPL_(55712)、超氧化物歧化酶、过氧化氢酶、疏甲丙脯酸及心得安等均对PA的缺氧性收缩反应无明显影响。结果提示PA的缺氧性收缩反应具内皮依赖性,其机制可能与缺氧抑制了EDRFs的作用有关。
Hypoxic vasoconstriction was studied in isolated rings of pig intrapulmonary(PA) with or without endothelium. Arterial rings were suspended in modified Krebs' bic-arbonate solution for isometric recording. Hypoxia was induced by changing the bubblinggas mixture in the chamber from, 95% O_2-5%CO_2 to 95%N_2-5%CO_2. When PA ringswere prestimulated with phenylephrine (PE, 2×10^(-6) mol/L), hypoxia could induce contrac-ctions in PA (0.86±0.09g, n=12). Removal of the endothelium decreased the hypoxicontractions of PA significantly (tension increment 0.11±0.03g, n=12, P<0.01).Endothelium-derived relaxing factors inhibitors: gossypol (10^(-5)mol/L), and methyleneblue (10^(-5)mol/L), prevented the hypoxia induced contraction of PA rings with intactendothelium. Inhibitors of cyclooxygenase, lipooxygenase, TXA_2 synthetase, angiotensin-converting enzyme or inhibitors of adrenergic, LTs', histaminic receptors and oxygen freeredical scavergers did not prevent the response to hypoxia. Verapamil (10^(-5)mol/L)significanily inhibited the vasoconstriction induced by hypoxia in PA (n=8, P<0.01)with intact endothelium. These results indicated that hypoxic contraction of PA wasendothelium dependent, and perhaps hypoxia inhibited the action of endothelium derivedrelaxing factors
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
1993年第6期694-698,共5页
Chinese Journal of Pathophysiology
关键词
肺动脉
内皮
缺氧
Pulmonary Artery
Hypoxia
Endothelium
