Cytoplasmic and nuclear binding of estradiol in the brain and pituitary of old female rats.
Cytoplasmic and nuclear binding of estradiol in the brain and pituitary of old female rats.
复制标题
老年雌性大鼠大脑和垂体中雌二醇的细胞质和核结合。
作者：
M. Jiang;M. Peng
研究了3-6月龄的年轻成年雌性大鼠和18月龄以上的老年雌性大鼠体内给药3h -雌二醇、胞浆和核雌激素受体后雌二醇的亚细胞分布。经静脉注射3h -雌二醇，加或不加去己烯雌酚预处理后，老龄非环（NC）大鼠垂体、下丘脑背侧和皮质杏仁核（AMYG）的胞质摄取显著增加，同时视前区（POA）和下丘脑基底内侧（BMH）的核摄取显著降低，AMYG和垂体的核摄取呈降低趋势。与幼龄大鼠相比，NC大鼠子宫的每毫克湿重蛋白质毫克数比较低，注射后1 h的核结合以每毫克体重每分钟崩解数表示明显低于幼龄大鼠，而以每毫克蛋白质每分钟崩解数表示则不明显。3h -雌二醇体外培养后的细胞质和核雌激素受体检测显示，雌二醇对老年延长阴道角化（PVC）大鼠的AMYG、POA、BMH、垂体前叶和子宫核受体的增加没有反应。这些结果表明，在老年PVC大鼠中，雌二醇从细胞质到细胞核的转运似乎受到损害。
The subcellular distribution of estradiol following the in vivo administration of 3H-estradiol, cytosol and nuclear estrogen receptor after in vitro incubation with 3H-estradiol were studied in young adult female rats (3-6 months old) and old female rats (over 18 months old). After intravenous injection of 3H-estradiol, with or without deithylstilbestrol pretreatment, significantly higher cytosol uptake of estradiol in the pituitary, dorsal hypothalamus and corticomedial amygdala (AMYG) with concomitant significantly lower nuclear uptake in the preoptic area (POA) and basomedial hypothalamus (BMH) and a tendency of lower nuclear uptake in AMYG and pituitary of old noncyclic (NC) rats as compared with young adult female rats were observed. The uterus of NC rats had a low ratio of milligrams of protein per milligram wet weight as compared with young rats and the nuclear binding 1 h after the injection was significantly lower than that of young rats when the value was expressed as disintegrations per minute per milligram weight but not when expressed as disintegrations per minute per milligram protein. Assays of cytosol and nuclear estrogen receptor after in vitro incubation with 3H-estradiol revealed that old prolonged vaginal cornification (PVC) rats did not react estradiol priming with increased nuclear receptors in the pooled brain tissues of AMYG, POA and BMH, anterior pituitary and uterus. These results indicate that there seems to be an impaired translocation of estradiol from cytosol to nucleus in old PVC rats.