Hartley M L, Pennefather J N, Story M E
Biol Reprod. 1983 Apr;28(3):536-44. doi: 10.1095/biolreprod28.3.536.
The mechanical responses of field-stimulated preparations of the longitudinal and circular myometrium, and of the costo-uterine muscle of the guinea pig to adrenoceptor agonists have been examined on Days 1, 4, 10 and 15-16 of the estrous cycle. The alpha-adrenoceptor agonist, phenylephrine, was exclusively excitatory in all three preparations taken from animals at each of the cycle days studied. Concentration-response curves for phenylephrine in all three tissues were unaffected by the fluctuations in ovarian hormones occurring during the estrous cycle. Isoproterenol (1 nmol/1-5 mumol/1) usually inhibited field-stimulation-induced contractions of the longitudinal uterine layer and the costo-uterine muscle; higher doses usually caused enhancement of contractions. In neither tissue did the potency or maximum effect of this inhibitory agonist differ at differing cycle stages. In the circular myometrium, the inhibitory effects of isoproterenol were less consistently observed, particularly in preparations taken at proestrus (Days 15-16). It is concluded that, except perhaps in the circular myometrium at proestrus, the fluctuations in ovarian hormones occurring during the estrous cycle in this species are insufficient to modify uterine responses mediated via alpha- and beta-adrenoceptors. It remains to be established whether the steroid hormones are capable of modulating responses mediated by adrenoceptors in the costo-uterine muscle.
在动情周期的第1、4、10天以及第15 - 16天，研究了豚鼠子宫纵肌层、环肌层及肋子宫肌的场刺激标本对肾上腺素能受体激动剂的机械反应。在研究的动情周期的每一天所取的全部三种标本中，α - 肾上腺素能受体激动剂去氧肾上腺素均表现为兴奋性。在所有三种组织中，去氧肾上腺素的浓度 - 反应曲线不受动情周期中卵巢激素波动的影响。异丙肾上腺素（1纳摩尔/升 - 5微摩尔/升）通常抑制子宫纵肌层和肋子宫肌的场刺激诱导的收缩；较高剂量通常导致收缩增强。在不同的周期阶段，这种抑制性激动剂在这两种组织中的效能或最大效应均无差异。在子宫环肌层，异丙肾上腺素的抑制作用较少一致地观察到，尤其是在动情前期（第15 - 16天）所取的标本中。得出的结论是，除了可能在动情前期的子宫环肌层外，该物种动情周期中卵巢激素的波动不足以改变通过α和β肾上腺素能受体介导的子宫反应。类固醇激素是否能够调节肋子宫肌中由肾上腺素能受体介导的反应仍有待确定。
