【摘要】 目的：研究异丙肾上腺素产生的人类脐静脉血管舒张是否内皮和 Ｎ Ｏ 依赖的，由哪一种肾上腺素能受体亚型介导。　方法：利用器官组织浴血管环法测定血管张力的变化，观察去除内皮， Ｌ┐ Ｎ Ｍ Ｍ Ａ 抑制 Ｎ Ｏ 合成酶，和高选择性 β１ 和／或 β２ 受体拮抗剂使用前后异丙肾上腺素产生的血管张力的变化。　结果：异丙肾上腺素产生脐静脉环血管舒张，β２ 受体（但不是 β１ 受体）阻断内皮，抑制 Ｎ Ｏ Ｓ合成酶后，异丙肾上腺素的作用消失。　结论：异丙肾上腺素产生的人类脐静静脉血管舒张通过 β２ 受体亚型介导，是内皮和 Ｎ Ｏ 依赖的。更多还原

【Abstract】 Objectives:To determine whether vasorelaxant effect of isoprenaline is endothelium and nitric oxide (NO) dependent, and which adrenoceptor subtype mediates this relaxation in human umbilical vein.\ Methods:The organ bath of rings of human umbilical vein was used to determine changes of tension of vessel in response to isoprenaline after removal of endothelium, coincubated with nitric oxide syntheses (NOS) inhibitor L NMMA, high selective β1 and/or β2 adrenoceptor antagonists.\ Results:Isoprenaline relaxed human umbilical vein rings, and this vasorelaxation was abolished by β 2 (but not β 1) adrenoceptor blockade, and by endothelium removal or 1 mmol/L L NMMA.\ Conclusions: Human umbilical vein relaxation in response to β adrenergic stimulation is mediated through β 2 adrenoceptor subtype, and dependent on endothelial NO production.更多还原