Jansson J O, Carlsson L, Isaksson O G
Endocrinology. 1985 Jan;116(1):95-8. doi: 10.1210/endo-116-1-95.
The long term in vivo effects of the recently characterized human pancreas GH-releasing factor, hpGRF (1-44) were studied in chronically cannulated unrestrained rats. In order to minimize the influence of endogenous hypothalamic GRF and somatostatin on the pituitary, the experiments were carried out in rats with the pituitary autotransplanted to the kidney capsule. The integrated GH release (mean +/- SE) in response to an iv injection of hpGRF (4 micrograms/kg) was markedly enhanced (P less than 0.01) by iv pretreatment with hpGRF every 8 h for 3 days (182 +/- 47 h X ng/ml) as compared to saline-pretreated controls (36 +/- 4 h X ng/ml). TRH pretreatment did not potentiate the effect of hpGRF (47 +/- 9 h X ng/ml). It is concluded that multiple administrations of hpGRF enhance the GH response to a subsequent hpGRF injection in the rat. Moreover, autotransplantation of the pituitary to the kidney capsule may supply a useful in vivo model for further studies on the effects of different modes of GRF administration on GH secretion.
在长期经皮插管且不受限制的大鼠中，研究了最近鉴定出的人胰腺生长激素释放因子hpGRF (1 - 44) 的长期体内效应。为了尽量减少内源性下丘脑生长激素释放因子和生长抑素对垂体的影响，实验在垂体自体移植到肾包膜的大鼠中进行。与生理盐水预处理的对照组 (36±4 h×ng/ml) 相比，每8小时静脉注射hpGRF 3天 (182±47 h×ng/ml) 后，静脉注射hpGRF (4微克/千克) 引起的生长激素释放积分 (平均值±标准误) 显著增强 (P<0.01)。促甲状腺激素释放激素预处理不能增强hpGRF的作用 (47±9 h×ng/ml)。结论是多次给予hpGRF可增强大鼠对随后hpGRF注射的生长激素反应。此外，垂体自体移植到肾包膜可为进一步研究生长激素释放因子不同给药方式对生长激素分泌的影响提供一个有用的体内模型。
