Katakami H, Downs T R, Frohman L A
Endocrinology. 1987 Mar;120(3):1079-82. doi: 10.1210/endo-120-3-1079.
The possible regulation of hypothalamic GH-releasing factor (GRF) by GH was studied in untreated and GH-treated hypophysectomized rats by measurement of rat hypothalamic GRF content and release in vitro with a specific GRF RIA. Two weeks after hypophysectomy, animals not receiving hormone replacement showed a marked reduction in hypothalamic GRF content (to 28% of sham-operated control values; P less than 0.001). Replacement therapy with T4, cortisone, and testosterone for 9 days did not correct the decrease in hypothalamic GRF content in hypophysectomized rats, though the addition of GH therapy partially restored GRF levels (to 55% of control values; P less than 0.001). GRF release from incubated mediobasal hypothalamic fragments of hypophysectomized rats was decreased both basally and in response to 30 mM K+. This defect was completely corrected by prior GH treatment. The results suggest an impairment of GRF synthesis and release in the presence of GH deficiency.
通过用特异性生长激素释放因子（GRF）放射免疫分析法测量大鼠下丘脑GRF含量及体外释放，研究了生长激素（GH）对未治疗及GH治疗的垂体切除大鼠下丘脑GRF的可能调节作用。垂体切除术后两周，未接受激素替代治疗的动物下丘脑GRF含量显著降低（降至假手术对照组值的28%；P<0.001）。用甲状腺素、可的松和睾酮进行9天的替代治疗未能纠正垂体切除大鼠下丘脑GRF含量的降低，尽管添加GH治疗可部分恢复GRF水平（至对照组值的55%；P<0.001）。垂体切除大鼠孵育的下丘脑中间基底部碎片基础状态下及对30 mM钾离子反应时的GRF释放均降低。预先进行GH治疗可完全纠正这一缺陷。结果提示，在生长激素缺乏的情况下，GRF的合成及释放受损。
