Aging impairs estrogenic suppression of hypothalamic proopiomelanocortin messenger ribonucleic acid in the mouse.
Aging impairs estrogenic suppression of hypothalamic proopiomelanocortin messenger ribonucleic acid in the mouse.
复制标题
衰老会损害小鼠下丘脑阿黑皮素原信使核糖核酸的雌激素抑制。
DOI：
10.1159/000126181
复制
发表时间：
1992
影响因子：
4.1
通讯作者：
Nelson,JF
中科院分区：
文献类型：
--
作者：
Karelus,K;Nelson,JF
神经内分泌对雌激素的敏感性改变是雌性啮齿动物生殖衰老的一个特征，但其分子基础尚不清楚。本研究的目的是确定雌激素(E_2)对下丘脑前阿片黑素皮质素(POMC)mRNA的调节变化是否是衰老小鼠神经内分泌对雌激素敏感性降低的一个组成部分。青年(4月龄)、中年(13月龄)和老年(25月龄)C57BL/6J小鼠摘除卵巢，2周后植入含E2或胆固醇的硅胶胶囊，3天后处死。使用与小鼠POMC基因片段互补的RNA探针，采用溶液杂交/核糖核酸酶保护法测定下丘脑POMC基因的表达。在植入Chol的组中，中年和老年小鼠的POMC mRNA比年轻小鼠低36%。雌二醇组幼鼠POMC基因表达水平降低44%，中老年动物POMC基因表达水平下降不明显。这些结果证实了衰老啮齿动物下丘脑POMC mRNA水平降低的早期证据，并表明E2降低下丘脑POMC mRNA的能力在中年时丧失。
Altered neuroendocrine sensitivity to estrogen is a characteristic of reproductive aging in female rodents, but its molecular basis is not well understood. The objective of this study was to determine whether altered modulation of hypothalamic proopiomelanocortin (POMC) mRNA by estradiol (E2) is a component of reduced neuroendocrine sensitivity to estrogen in the aging mouse. Young (4 month-old), middle-aged (13 month-old), and old (25 month-old) C57BL/6J mice were ovariectomized, implanted 2 weeks later with Silastic capsules containing E2or cholesterol (CHOL), and sacrificed 3 days later. Hypothalamic POMC mRNA was measured by solution hybridization/RNase protection, using a RNA probe complementary to a fragment of mouse POMC mRNA. In the group with CHOL implants, POMC mRNA was 36% lower in middle-aged and old mice compared to young mice. E2treatment reduced POMC mRNA levels by 44% in young mice but failed to lower POMC mRNA in middle-aged and old animals. These results confirm earlier evidence of reduced levels of POMC mRNA in hypothalami of aging rodents and indicate that the ability of E2to reduce hypothalamic POMC mRNA is lost by middle age.