Cunard C M, Maddox Y T, Ramwell P W
J Pharmacol Exp Ther. 1986 Apr;237(1):82-5.
The pulmonary arteries of rats were studied in order to determine the existence of sexual dimorphism. Gender differences, in the sensitivity (EC50) and maximum contractility (Tmax) of ring preparations of the main pulmonary arteries of adult male and female rats, were evaluated with the synthetic endoperoxide analog [(15S)]-hydroxy-11 alpha,9 alpha-(epoxymethano)-prosta-5Z, 13E-dienoic acid,] (U46619) and norepinephrine. There were no significant gender differences in the Tmax values obtained with either U46619 or norepinephrine. However, when the intimal surface of vessel segments from female rats was rubbed, U46619 but not norepinephrine elicited a significantly lower Tmax. In contrast, no change in Tmax was observed with denuded vessel segments from males. Removal of the endothelium did not significantly affect the EC50 of U46619 or norepinephrine in segments from either sex. The inhibitory effect of verapamil on the U46619-induced contractile response was studied on both intact and denuded vessels from rats of both gender. The Tmax of intact vessels from males but not females was significantly attenuated by verapamil (P less than .05). The EC50 values with verapamil were not significantly different in any of the vessel preparations. We suggest that the endothelium of the pulmonary artery of female rats significantly potentiates the contractile response to U46619 and attenuates the inhibitory effect of verapamil.
为了确定性别差异是否存在，对大鼠的肺动脉进行了研究。用合成内过氧化物类似物[(15S)]-羟基-11α,9α-(环氧亚甲基)-前列腺-5Z,13E-二烯酸](U46619)和去甲肾上腺素评估成年雄性和雌性大鼠主肺动脉环制剂在敏感性(EC50)和最大收缩力(Tmax)方面的性别差异。用U46619或去甲肾上腺素获得的Tmax值没有显著的性别差异。然而，当摩擦雌性大鼠血管段的内膜表面时，U46619而非去甲肾上腺素引起的Tmax显著降低。相比之下，雄性大鼠剥脱血管段未观察到Tmax的变化。去除内皮对两性血管段中U46619或去甲肾上腺素的EC50没有显著影响。研究了维拉帕米对两性大鼠完整和剥脱血管上U46619诱导的收缩反应的抑制作用。维拉帕米显著减弱了雄性而非雌性完整血管的Tmax(P<0.05)。在任何血管制剂中，维拉帕米的EC50值均无显著差异。我们认为，雌性大鼠肺动脉内皮显著增强了对U46619的收缩反应，并减弱了维拉帕米的抑制作用。
