Adam S P, Hartley M L, Pennefather J N, Story M E, Handberg G M
J Auton Pharmacol. 1985 Dec;5(4):317-24. doi: 10.1111/j.1474-8673.1985.tb00556.x.
The influence of ovarian steroids upon responses to electrical stimulation and to activation of adrenoreceptors in field-stimulated preparations of longitudinal and circular myometrium from ovariectomised guinea-pigs has been investigated. Adult virgin guinea-pigs were bilaterally ovariectomised and were treated two weeks later with thrice-weekly injections of oestradiol cypionate for two weeks, or treated as in then given oestradiol cypionate and progesterone for a further four days. Control groups of bilaterally ovariectomised and sham ovariectomised animals remained untreated. Both myometrial layers from untreated ovariectomised guinea-pigs were atrophied. Responses to field stimulation in the circular myometrium were much smaller than those in the longitudinal layer. Steroid pretreatment, most notably treatment with oestradiol and progesterone, were associated with decreased and increased responsiveness to electrical stimulation in the circular and longitudinal myometrial layers respectively. Adrenaline and noradrenaline were consistently excitatory on preparations of circular myometrium from ovariectomised animals. Responses comprised either enhancement of electrically-evoked contractions, or, with the higher concentrations, the appearance of rapid contractions superimposed upon an increase in basal tone. The latter effects were also evident in preparations of circular myometrium from sham operated animals. In preparations of longitudinal myometrium from untreated ovariectomised animals noradrenaline consistently and adrenaline usually caused a simple enhancement of the magnitude of the evoked contractions. Phentolamine reduced the excitatory effects of both amines in both layers. In circular myometrium from the oestrogen-treated group both catecholamines produced phentolamine-sensitive enhancement of electrically-evoked contractions, but did not cause high frequency contractions or increased tonus. Noradrenaline and adrenaline produced qualitatively similar phentolamine-sensitive effects in preparations of longitudinal myometrium from this group.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了卵巢类固醇对去卵巢豚鼠纵向和环形子宫肌层的电场刺激反应以及肾上腺素能受体激活反应的影响。成年未孕豚鼠双侧去卵巢，两周后每周三次注射环戊丙酸雌二醇，持续两周，或按此处理后再给予环戊丙酸雌二醇和孕酮，持续四天。双侧去卵巢和假去卵巢动物的对照组未接受治疗。未治疗的去卵巢豚鼠的两层子宫肌层均萎缩。环形子宫肌层对电场刺激的反应比纵向肌层小得多。类固醇预处理，尤其是雌二醇和孕酮治疗，分别与环形和纵向子宫肌层对电刺激的反应性降低和增加有关。肾上腺素和去甲肾上腺素对去卵巢动物的环形子宫肌层制剂始终具有兴奋作用。反应包括增强电诱发的收缩，或者在较高浓度下，在基础张力增加的基础上出现快速收缩。后一种效应在假手术动物的环形子宫肌层制剂中也很明显。在未治疗的去卵巢动物的纵向子宫肌层制剂中，去甲肾上腺素始终使诱发收缩的幅度简单增强，而肾上腺素通常也会如此。酚妥拉明降低了两层中两种胺的兴奋作用。在雌激素处理组的环形子宫肌层中，两种儿茶酚胺均产生酚妥拉明敏感的电诱发收缩增强，但未引起高频收缩或张力增加。去甲肾上腺素和肾上腺素在该组纵向子宫肌层制剂中产生了定性相似的酚妥拉明敏感效应。（摘要截短于250字）
