Hormonal regulation of rat hypothalamic neuropeptide mRNAs: effect of hypophysectomy and hormone replacement on growth-hormone-releasing factor, somatostatin and the insulin-like growth factors.
Hormonal regulation of rat hypothalamic neuropeptide mRNAs: effect of hypophysectomy and hormone replacement on growth-hormone-releasing factor, somatostatin and the insulin-like growth factors.
复制标题
大鼠下丘脑神经肽 mRNA 的激素调节：垂体切除术和激素替代对生长激素释放因子、生长抑素和胰岛素样生长因子的影响。
DOI：
10.1159/000125732
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发表时间：
1991
影响因子：
4.1
通讯作者：
McKelvy,JF
中科院分区：
文献类型：
--
作者：
Wood,TL;Berelowitz,M;Gelato,MC;RobertsJr,CT;LeRoith,D;Millard,WJ;McKelvy,JF
通过测定雄性垂体切除大鼠在有或无甲状腺激素、皮质酮、睾酮或GH替代的情况下稳态mRNA水平，研究了参与生长激素（GH）调节的下丘脑肽类的激素反馈调节。垂体切除后下丘脑GH释放因子（GRF）mRNA水平逐渐增加，15天后达到假手术水平的420%，而下丘脑胰岛素样生长因子I（IGF-I）和胰岛素样生长因子II（IGF-II）mRNA水平下降至假手术水平的40%以下。整个下丘脑生长抑素mRNA水平与假手术组无显著差异。一周的连续GH输注恢复下丘脑IGF-I mRNA的水平（95%）与那些在假手术对照无区别，但对IGF-II或GRF mRNA没有影响。甲状腺激素，皮质酮和睾酮治疗没有GH对垂体切除术诱导的IGF-I或IGF-II mRNA水平的降低没有影响，但逆转了GRF mRNA的升高。我们的结论是，下丘脑IGF-I可能参与GH反馈调节，因此可能作为下丘脑GH的调制器。与此相反，IGF-II可能受垂体促激素之一的调节，但不受GH或测试的靶激素的调节。最后，下丘脑GRF mRNA的调节似乎是复杂的，可能包括靶激素反馈。
Hormonal feedback regulation of hypothalamic peptides putatively involved in growth hormone (GH) regulation has been studied by measurement of steady-state mRNA levels in male hypophysectomized rats with or without thyroid hormone, corticosterone, testosterone or GH replacement. Hypothalamic GH-releasing factor (GRF) mRNA levels increased progressively following hypophysectomy to 420% of sham levels after 15 days while hypothalamic insulin-like growth factor I (IGF-I) and insulin-like growth factor II (IGF-II) mRNA levels decreased to less than 40% of sham levels. Whole hypothalamic somatostatin mRNA levels were not significantly different from sham. One week of continuous GH infusion restored hypothalamic IGF-I mRNA to levels (95%) indistinguishable from those in sham-operated controls but had no effect on either IGF-II or GRF mRNA. Thyroid hormone, corticosterone and testosterone treatment without GH had no effect on the hypophysectomy-induced reduction of either IGF-I or IGF-II mRNA levels but reversed the elevation of GRF mRNA. We conclude that hypothalamic IGF-I may be involved in GH feedback regulation and thus may function as a hypothalamic modulator of GH. In contrast, IGF-II may be regulated by one of the pituitary trophic hormones but not by GH or the target hormones tested. Finally, hypothalamic GRF mRNA regulation appears to be complex and may include target hormone feedback.