Mason B D, Van Petten G R
Am J Obstet Gynecol. 1978 Aug 15;131(8):868-71. doi: 10.1016/s0002-9378(16)33134-9.
The effects of imipramine and amitriptyline on the responses of the uteroplacental vasculature to norepinephrine and phenylephrine were investigated in the pregnant ewe. Experiments were performed on conscious animals in which electromagnetic flow transducers were chronically implanted on the uterine arteries. Administered alone, the tricyclic antidepressants had no effect on mean arterial pressure (MAP) or estimated uteroplacental vascular conductance (UPVCe). Following intravenous infusion of either imipramine (1 mg. per kilogram) or amitriptyline (2.5 mg. per kilogram), the pressor response to norepinephrine (1 microgram per kilogram) and the duration of that response were significantly increased (p less than 0.05). In addition, both the duration of the norepinephrine-produced decrease in uteroplacental blood flow (UPBF) and the amplitude of the decrease in UPVCe were enhanced. In contrast, responses to phenylephrine (2.5 microgram per kilogram) were unaffected by prior administration of either imipramine or amitriptyline. Of additional interest were findings suggesting differential sensitivities to alpha-agonists of the uteroplacental compared with other vascular beds. These observations bring attention to the possibility of interactions between endogenous or exogenous norepinephrine and the tricyclic antidepressants and suggest that the possibly unique sensitivities of the uteroplacental bed should be considered when prescribing drugs during pregnancy.
在怀孕母羊中研究了丙咪嗪和阿米替林对子宫胎盘血管系统对去甲肾上腺素和去氧肾上腺素反应的影响。实验在清醒动物身上进行，电磁流量传感器被长期植入子宫动脉。单独使用时，三环类抗抑郁药对平均动脉压（MAP）或估计的子宫胎盘血管传导率（UPVCe）没有影响。静脉输注丙咪嗪（每公斤1毫克）或阿米替林（每公斤2.5毫克）后，对去甲肾上腺素（每公斤1微克）的升压反应及其持续时间显著增加（p<0.05）。此外，去甲肾上腺素引起的子宫胎盘血流量（UPBF）减少的持续时间和UPVCe减少的幅度均增强。相比之下，对去氧肾上腺素（每公斤2.5微克）的反应不受丙咪嗪或阿米替林预先给药的影响。另外有趣的是，研究结果表明子宫胎盘对α激动剂的敏感性与其他血管床不同。这些观察结果引起了对内源性或外源性去甲肾上腺素与三环类抗抑郁药之间相互作用可能性的关注，并表明在孕期开药时应考虑子宫胎盘床可能具有的独特敏感性。
