Iqbal J, Swanson J J, Prins G S, Jacobson C D
Department of Veterinary Anatomy and Neuroscience Program, Iowa State University, Ames, 50011, USA.
Brain Res. 1995 Dec 12;703(1-2):1-18. doi: 10.1016/0006-8993(95)00983-3.
Androgens are involved in a variety of centrally mediated functions after binding to their intracellular receptors. In the present report, we have employed the androgen receptor antibody, PG-21, and indirect immunohistochemistry to examine the distribution of cells containing androgen receptor-like immunoreactivity (AR-IR) in the intact adult male Brazilian opossum brain and pituitary. Additional adult males were castrated to examine the effects of withdrawal of circulating androgens and testosterone replacement on AR-IR. Immunoblots and immunohistochemical controls demonstrated that the androgen receptor in the opossum brain and peripheral tissues are of a similar molecular mass as to has been reported for the rat. Cells containing AR-IR were widely distributed throughout the brain of intact adult males. The highest number of immunoreactive cells were present in the dorsal and ventral nuclei of the lateral septum, medial division of the bed nucleus of the stria terminalis, medial preoptic area, median preoptic nucleus, nucleus of the lateral olfactory tubercle, central amygdaloid nucleus, anterior cortical amygdaloid nucleus, posterior amygdaloid nucleus, subiculum, ventromedial hypothalamic nucleus, arcuate-median eminence region, and ventral premammillary nucleus. The anterior pituitary gland also contained a high number of cells containing AR-IR. The general distribution of AR-IR both in the brain and anterior pituitary gland resembled that reported for other mammalian species. Castration of the adult males four days prior to perfusion eliminated androgen receptor immunostaining throughout the brain except for a few lightly immunostained cells in the ventral nucleus of the lateral septum and stria terminalis. Androgen receptor immunostaining was decreased in the anterior pituitary gland following castration and became cytoplasmic. Testosterone administration 2 h before perfusion restored AR-IR both in the brain and anterior pituitary gland. These data suggested that immunohistochemical detection of bound (nuclear) androgen receptors as seen with PG-21 antibody in the brain and anterior pituitary gland of the opossum is dependent upon circulating androgens. Further, the wide distribution and similarity in localization of androgen receptors in the opossum brain and anterior pituitary gland to that of other species suggests that androgen receptors might be involved in similar functions in the opossum as has been reported for other species.
雄激素与细胞内受体结合后参与多种中枢介导的功能。在本报告中，我们使用雄激素受体抗体PG - 21和间接免疫组织化学方法，研究成年雄性巴西负鼠完整大脑和垂体中含有雄激素受体样免疫反应性（AR - IR）的细胞分布。另外对成年雄性进行去势手术，以研究循环雄激素撤除和睾酮替代对AR - IR的影响。免疫印迹和免疫组织化学对照表明，负鼠大脑和外周组织中的雄激素受体分子量与大鼠中报道的相似。含有AR - IR的细胞广泛分布于成年雄性完整大脑中。免疫反应性细胞数量最多的区域是外侧隔核的背侧和腹侧核、终纹床核的内侧部、视前内侧区、视前正中核、外侧嗅结节核、杏仁中央核、杏仁前皮质核、杏仁后核、海马下脚、下丘脑腹内侧核、弓状 - 正中隆起区域和腹侧乳头前核。垂体前叶也含有大量含有AR - IR的细胞。大脑和垂体前叶中AR - IR的总体分布与其他哺乳动物物种报道的相似。灌注前四天对成年雄性进行去势，除了外侧隔核腹侧和终纹床核中有少数轻度免疫染色的细胞外，整个大脑的雄激素受体免疫染色消失。去势后垂体前叶的雄激素受体免疫染色减少并变为细胞质染色。灌注前2小时给予睾酮可使大脑和垂体前叶的AR - IR恢复。这些数据表明，用PG - 21抗体在负鼠大脑和垂体前叶中检测到的结合型（核）雄激素受体的免疫组织化学检测依赖于循环雄激素。此外，负鼠大脑和垂体前叶中雄激素受体的广泛分布及其定位与其他物种的相似性表明，雄激素受体在负鼠中可能参与与其他物种报道的类似功能。
