ABSTRACT

This study investigates the relationships between the pituitary-adrenal axis and the ovarian activity in the cyclic goat reared under arid environment. Plasma hormone levels are assessed on blood samples collected weekly at 9:00 a.m., during one year. The ovarian activity is characterized by an anestrous period from mid-March to mid-July and a breeding period during the rest of the year. Adrenal histomorphometry and immunolocalization of Estrogen Receptors α (ERα) and Progesterone Receptors (PR) were performed on adrenal glands collected during each season. During the anestrous period, all adrenal compartments appeared enlarged, as did cellular and nuclear areas. ERα and PR immunostaining were identified in all the adrenal gland zonae with more intensity for the ERα. ERα immunostaining is greater in zona fasciculata whereas PR immunostaining is more intense in zona fasciculata and zona reticularis during the breeding season. Plasma ACTH shows no difference between the two seasons, while cortisol rises slightly during the anestrous period. There is a negative but not significant correlation between progesterone levels with plasma ACTH and cortisol. The pituitary-adrenal axis is activated essentially at the anestrous onset and at the ovarian resumption which represents stressful events, but it varies slightly between these two seasons in this goat.

摘要

本研究调查了在干旱环境下饲养的循环山羊的垂体-肾上腺轴与卵巢活动之间的关系。血浆激素水平在一年中每周上午 9:00 采集的血样上进行评估。卵巢活动的特点是从 3 月中旬到 7 月中旬处于无发情期，并在一年中的其余时间处于繁殖期。对每个季节收集的肾上腺进行肾上腺组织形态测定和雌激素受体 α (ERα) 和孕酮受体 (PR) 的免疫定位。在无动情期，所有肾上腺区室都出现扩大，细胞和核区也是如此。在所有肾上腺带中鉴定出 ERα 和 PR 免疫染色，其中 ERα 的强度更高。在繁殖季节，束状带中的 ERα 免疫染色更强，而束状带和网状带中的 PR 免疫染色更强烈。血浆 ACTH 显示两个季节之间没有差异，而皮质醇在无情期略有上升。孕酮水平与血浆 ACTH 和皮质醇之间存在负但不显着的相关性。垂体 - 肾上腺轴基本上在无动情发作和卵巢恢复时被激活，这代表压力事件，但在这只山羊的这两个季节之间略有不同。孕酮水平与血浆 ACTH 和皮质醇之间存在负但不显着的相关性。垂体 - 肾上腺轴基本上在无动情发作和卵巢恢复时被激活，这代表压力事件，但在这只山羊的这两个季节之间略有不同。孕酮水平与血浆 ACTH 和皮质醇之间存在负但不显着的相关性。垂体 - 肾上腺轴基本上在无动情发作和卵巢恢复时被激活，这代表压力事件，但在这只山羊的这两个季节之间略有不同。