Guillaume V, Magnan E, Cataldi M, Dutour A, Sauze N, Renard M, Razafindraibe H, Conte-Devolx B, Deghenghi R, Lenaerts V
Laboratoire de Neuroendocrinologie Expérimentale, Institut Fédératif Jean Roche, INSERM U-297, Faculté de Médecine Nord, Marseille, France.
Endocrinology. 1994 Sep;135(3):1073-6. doi: 10.1210/endo.135.3.7915227.
The acute effect of a new GH-releasing peptide, hexarelin (1 mg, iv), on GH secretion and the mechanisms involved in its changes were investigated in conscious sheep. Peripheral GH levels and GH-releasing hormone (GHRH) and somatostatin concentrations in hypophysial portal blood were measured in six rams. An increase in jugular GH levels was observed 15 min after hexarelin injection (9.1 +/- 1.8 vs. 3.9 +/- 0.8 ng/ml; P < 0.05). This was associated with a stimulation of GHRH release into hypophysial portal blood (145.4 +/- 19.9 vs. 59.2 +/- 10.8 pg/ml; P < 0.01) without a change in somatostatin secretion. Our data indicate that GH-releasing peptide-induced GH stimulation in the sheep involves an activation of GHRH neurons in addition to the previously demonstrated direct effect on the pituitary cells.
在清醒的绵羊中研究了一种新型生长激素释放肽六元瑞林（1毫克，静脉注射）对生长激素分泌的急性作用及其变化所涉及的机制。在六只公羊中测量了外周生长激素水平以及垂体门脉血中生长激素释放激素（GHRH）和生长抑素的浓度。注射六元瑞林15分钟后，观察到颈静脉生长激素水平升高（9.1±1.8对3.9±0.8纳克/毫升；P<0.05）。这与垂体门脉血中GHRH释放的刺激有关（145.4±19.9对59.2±10.8皮克/毫升；P<0.01），而生长抑素分泌没有变化。我们的数据表明，生长激素释放肽诱导的绵羊生长激素刺激除了先前证明的对垂体细胞的直接作用外，还涉及GHRH神经元的激活。
