Handa R J, Connolly P B, Resko J A
Department of Physiology, Oregon Health Sciences University, Portland 97201.
Endocrinology. 1988 May;122(5):1890-6. doi: 10.1210/endo-122-5-1890.
In this study we compared the binding characteristics of methyltrienolone (R1881) in pooled cytosols from the hypothalamus-preoptic area-amygdala-septum (HPAS) of adult and fetal rhesus macaques. In addition, we studied the ontogeny of cytosolic androgen receptors (AR) in fetal neural tissue. Intact adult males and fetal rhesus monkeys of known gestational age were our experimental subjects. Fetuses were delivered by cesarean section at 50, 65, 80, and 150 days gestation. HPAS cytosols from 150-day fetuses and adult males were incubated with the synthetic ligand, [3H]R1881, for determining AR characteristics and to validate the assay. A single high affinity, low capacity receptor for R1881 was found in HPAS cytosols. The apparent dissociation constant was similar between adult and fetal HPAS (1.09 X 10(-10) vs. 1.59 X 10(-10) M, respectively). Binding specificity was determined by the addition of excess radioinert testosterone (T), 5 alpha-dihydrotestosterone, estradiol, or progesterone to the incubation tube. R1881 binding was displaced by the addition of excess amounts of T and dihydrotestosterone, but not of estradiol or progesterone. There were no differences between fetal and adult animals. Single point analyses of AR numbers in fetal animals showed significant age and regional differences (P less than 0.05). Since no sex differences were apparent, data from males and females were combined. In the hypothalamus-preoptic area there was a significant increase in AR throughout gestation [1.3 +/- 0.4 (+/- SE) fmol/mg protein; n = 7 (50 days gestation) vs. 6.2 +/- 0.3 fmol/mg protein; n = 4 (150 days of gestation); P less than 0.01]. These values differed significantly from adult male hypothalamic-preoptic area (14.1 +/- 0.3 fmol/mg protein; P less than 0.01; n = 3). AR levels in frontal and temporal cortex were high on day 50 of gestation, but showed a significant decline by day 150 (P less than 0.05). The administration of testosterone propionate (25 mg/kg.day) to pregnant animals from 40-50 days gestation, which resulted in elevated levels of serum T in female, but not male, fetuses had no effect on AR in any brain region studied. These studies confirm the presence of AR in fetal monkey brain. New information is provided on the changes in AR numbers in cortical and hypothalamic tissues during the critical period for sexual differentiation of the primate brain.(ABSTRACT TRUNCATED AT 250 WORDS)
在本研究中，我们比较了成年和胎儿恒河猴下丘脑 - 视前区 - 杏仁核 - 隔区（HPAS）混合胞液中甲基三烯醇酮（R1881）的结合特性。此外，我们研究了胎儿神经组织中胞质雄激素受体（AR）的个体发育。成年雄性恒河猴和已知胎龄的胎儿恒河猴是我们的实验对象。在妊娠50、65、80和150天时通过剖宫产取出胎儿。将150天胎儿和成年雄性的HPAS胞液与合成配体[3H]R1881一起孵育，以确定AR特性并验证该检测方法。在HPAS胞液中发现了一种单一的高亲和力、低容量的R1881受体。成年和胎儿HPAS的表观解离常数相似（分别为1.09×10⁻¹⁰和1.59×10⁻¹⁰ M）。通过向孵育管中加入过量的放射性惰性睾酮（T）、5α - 二氢睾酮、雌二醇或孕酮来确定结合特异性。加入过量的T和二氢睾酮可取代R1881的结合，但雌二醇或孕酮则不能。胎儿和成年动物之间没有差异。对胎儿动物AR数量的单点分析显示出显著的年龄和区域差异（P＜0.05）。由于未发现明显的性别差异，因此将雄性和雌性的数据合并。在整个妊娠期，下丘脑 - 视前区的AR显著增加[1.3±0.4（±SE）fmol/mg蛋白；n = 7（妊娠50天）对6.2±0.3 fmol/mg蛋白；n = 4（妊娠150天）；P＜0.01]。这些值与成年雄性下丘脑 - 视前区（14.1±0.3 fmol/mg蛋白；P＜0.01；n = 3）有显著差异。妊娠50天时额叶和颞叶皮质的AR水平较高，但到150天时显著下降（P＜0.05）。在妊娠40 - 50天给怀孕动物注射丙酸睾酮（25 mg/kg·天），这导致雌性胎儿而非雄性胎儿的血清T水平升高，但对所研究的任何脑区的AR均无影响。这些研究证实了胎儿猴脑中存在AR。提供了关于灵长类动物脑性分化关键期皮质和下丘脑组织中AR数量变化的新信息。（摘要截断于250字）
