硝苯吡啶对兔输卵管活动和卵子运行的影响

钙道阻断剂硝苯吡啶(NIF)可明显延缓卵子在兔输卵管内的运行速度。在HCG处理的麻醉兔,NIF抑制输卵管的自发收缩,并说明减弱去甲肾上腺素(NA)和15-甲基PGF_2α所致输卵管腔内压升高和电活动增强。在离体兔输卵管环肌标本,NIF能明显压低NA使峡部和壶腹部环肌张力提高的浓度—反应曲线。以上提示NIF延缓兔卵子运行可能与其阻断钙通道,抑制平滑肌收缩和/或降低输卵管平滑肌对内源性NA和PGF_2α的反应性有关。

EFFECTS OF NIFEDIPINE ON OVIDUCT MOTILITY AND OVUM TRANSPORT IN RABBITS

Nifedipine (2 mg/kg×3, im) was found to significantly delay egg transport in rabbits 48 h after HCG injection. The mean distance of egg transport (X value)was 65.8±3.0 in nifedipine treated group and 80.0±1.7 in control group (p<0.01). In HCG treated anaesthetized rabbits, nifedipine inhibited the spontaneous oviduct activity and greatly reduced the noradrenaline- and 15-methyl PGF_2α-induced increase in oviduct intraluminal pressure and electrical activity. With isolated ampullary and isthmic circular muscle preparations, nifedipine markedly inhibited the doseresponse curve of noradrenaline. These results suggest that the effect of nifedipine on egg transport may be related to its blocking effect on calcium channel, inhibiting the contraction of oviduct smooth muscle, and/or decreasing the responsiveness of the oviduct to endogenous noradrenaline and PGF_2α.