Parent A, Schiffrin E L, St-Louis J
Experimental Hypertension Laboratory, Clinical Research Institute of Montreal, Quebec, Canada.
Am J Obstet Gynecol. 1990 Jul;163(1 Pt 1):229-34. doi: 10.1016/s0002-9378(11)90703-0.
Responses to adrenergic agents were measured on rings of mesenteric, artery of nonpregnant and pregnant rats at 21 days' gestation. In tissues from pregnant rats, norepinephrine, and phenylephrine were less sensitive than in rings from nonpregnant animals; maximum responses were not affected. The effect of isoproterenol was not modified in tissues from pregnant rats. The presence of endothelium in tissue rings was evaluated as fractional relaxation to acetylcholine. Sensitivity to phenylephrine and norepinephrine was inversely related to the effect of acetylcholine. This relationship was similar in slope in both groups but different in intercept. The sensitivity to isoproterenol was directly related to the presence of endothelium (curves similar in both slope and intercept). This demonstrates that the responses of mesenteric artery rings depends on the presence of endothelium. Furthermore, vascular endothelium is not involved in the blunted responses to adrenergic vasoconstrictor during pregnancy.
在妊娠21天的未孕和孕鼠肠系膜动脉环上测量对肾上腺素能药物的反应。在孕鼠组织中，去甲肾上腺素和去氧肾上腺素的敏感性低于未孕动物的动脉环；最大反应不受影响。异丙肾上腺素对孕鼠组织的作用未改变。组织环中内皮的存在通过对乙酰胆碱的分数舒张来评估。对去氧肾上腺素和去甲肾上腺素的敏感性与乙酰胆碱的作用呈负相关。两组的这种关系斜率相似但截距不同。对异丙肾上腺素的敏感性与内皮的存在直接相关（斜率和截距的曲线相似）。这表明肠系膜动脉环的反应取决于内皮的存在。此外，血管内皮不参与孕期对肾上腺素能血管收缩剂反应减弱的过程。
