Espinosa-Valdez Adriana, Flores Angélica, Arrieta-Cruz Isabel, Cárdenas Mario, Chavira Roberto, Domínguez Roberto, Cruz María Esther
Biology of Reproduction Research Unit, Laboratory of Neuroendocrinology, Facultad de Estudios Superiores Zaragoza, UNAM, AP 9-020, CP 15000, Mexico City, Mexico.
Department of Basic Research, National Institute of Geriatrics, México City, Mexico.
Reprod Biol Endocrinol. 2016 Nov 4;14(1):75. doi: 10.1186/s12958-016-0208-3.
Muscarinic receptors (mAChRs) of the preoptic and anterior hypothalamus areas (POA-AHA) regulate ovulation in an asymmetric manner during the estrous cycle. The aims of the present study were to analyze the effects of a temporal blockade of mAChRs on either side of the POA-AHA performed in diestrus-2 rats on ovulation, the levels of estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) and the mechanisms involved in changes in ovulation.
Cyclic rats on diestrus-2 day were anesthetized and randomly assigned to the following groups: 1) microinjection of 1 μl of saline or atropine solution (62.5 ng) in the left or right POA-AHA; 2) removal (unilateral ovariectomty, ULO) of the left (L-ULO) or right (R-ULO) ovary, and 3) rats microinjected with atropine into the left or right POA-AHA plus L-ULO or R-ULO. The ovulation rate and the number of ova shed were measured during the predicted estrus, as well as the levels of estradiol, FSH and LH during the predicted proestrus and the effects of injecting synthetic LH-releasing hormone (LHRH) or estradiol benzoate (EB).
Atropine in the left POA-AHA decreased both the ovulation rate and estradiol and LH levels on the afternoon of proestrus, also LHRH or EB injection restored ovulation. L- or R-ULO resulted in a lower ovulation rate and smaller number of ova shed, and only injection of LHRH restored ovulation. EB injection at diestrus-2 restored ovulation in animals with L-ULO only. The levels of estradiol, FSH and LH in rats with L-ULO were higher than in animals with unilateral laparotomy. In the group microinjected with atropine in the left POA-AHA, ovulation was similar to that in ULO rats. In contrast, atropine in the right POA-AHA of ULO rats blocked ovulation, an action that was restored by either LHRH or EB injection.
These results indicated that the removal of a single ovary at noon on diestrus-2 day perturbed the neuronal pathways regulating LH secretion, which was mediated by the muscarinic system connecting the right POA-AHA and the ovaries.
视前区和下丘脑前区（POA - AHA）的毒蕈碱受体（mAChRs）在发情周期中以不对称方式调节排卵。本研究的目的是分析在动情后期 - 2大鼠中对POA - AHA两侧进行毒蕈碱受体的暂时阻断对排卵、雌二醇、促卵泡激素（FSH）和促黄体生成素（LH）水平的影响以及排卵变化所涉及的机制。
将处于动情后期 - 2天的周期性大鼠麻醉，并随机分为以下几组：1）在左侧或右侧POA - AHA微量注射1μl生理盐水或阿托品溶液（62.5 ng）；2）切除左侧（L - ULO）或右侧（R - ULO）卵巢（单侧卵巢切除术，ULO），以及3）在左侧或右侧POA - AHA微量注射阿托品的大鼠加L - ULO或R - ULO。在预测的发情期测量排卵率和排出的卵子数量，以及在预测的发情前期测量雌二醇、FSH和LH水平，以及注射合成促黄体生成素释放激素（LHRH）或苯甲酸雌二醇（EB）的效果。
左侧POA - AHA注射阿托品降低了发情前期下午的排卵率以及雌二醇和LH水平，此外，注射LHRH或EB可恢复排卵。L - ULO或R - ULO导致排卵率降低和排出的卵子数量减少，并且仅注射LHRH可恢复排卵。在动情后期 - 2注射EB仅在L - ULO动物中恢复排卵。L - ULO大鼠的雌二醇、FSH和LH水平高于单侧剖腹手术的动物。在左侧POA - AHA微量注射阿托品的组中，排卵情况与ULO大鼠相似。相反，ULO大鼠右侧POA - AHA注射阿托品可阻断排卵，LHRH或EB注射可恢复此作用。
这些结果表明，在动情后期 - 2天中午切除单个卵巢扰乱了调节LH分泌的神经通路，这是由连接右侧POA - AHA和卵巢的毒蕈碱系统介导的。
