Torres-Alemán I, Debeljuk L, Schally A V
Peptides. 1985 Sep-Oct;6(5):993-5. doi: 10.1016/0196-9781(85)90333-x.
In order to study a possible direct action of LH-RH analogs on the pituitary lactotrophs, we investigated the effect of long-term in vivo pretreatment with D-Trp-6-LH-RH on in vitro secretion of PRL and luteinizing hormone (LH) by the pituitary glands from male and female rats. In vivo pretreatment with D-Trp-6-LH-RH (50 micrograms/day, SC) for 15 days greatly reduced basal in vitro PRL release (p less than 0.01) in female, but not in male pituitary glands. TRH-stimulated PRL secretion was not affected by pretreatment with D-Trp-6-LH-RH in female rats, but was impaired in male pituitaries. Acute in vitro exposure to D-Trp-6-LH-RH did not modify PRL secretion by female pituitary glands pretreated in vivo with the analog. However, this same in vivo pretreatment greatly decreased PRL release from male pituitaries (p less than 0.01). Basal in vitro LH release by male pituitary glands was partially lowered by in vivo pretreatment with D-Trp-6-LH-RH, as compared to controls (p less than 0.01), while basal LH release in female pituitaries remained at control levels. Finally, D-Trp-6-LH-RH-induced stimulation of in vitro LH release was severely impaired in female pituitaries (p less than 0.01) but only slightly reduced in the males.
为了研究促黄体生成素释放激素（LH-RH）类似物对垂体催乳细胞可能的直接作用，我们研究了用D-色氨酸-6-LH-RH进行长期体内预处理对雄性和雌性大鼠垂体体外分泌催乳素（PRL）和促黄体生成素（LH）的影响。用D-色氨酸-6-LH-RH（50微克/天，皮下注射）进行15天的体内预处理，可显著降低雌性垂体的基础体外PRL释放（p<0.01），但对雄性垂体无此作用。在雌性大鼠中，TRH刺激的PRL分泌不受D-色氨酸-6-LH-RH预处理的影响，但在雄性垂体中则受损。对体内用该类似物预处理的雌性垂体进行急性体外暴露于D-色氨酸-6-LH-RH，并未改变PRL分泌。然而，相同的体内预处理可显著降低雄性垂体的PRL释放（p<0.01）。与对照组相比，用D-色氨酸-6-LH-RH进行体内预处理可使雄性垂体的基础体外LH释放部分降低（p<0.01），而雌性垂体的基础LH释放则保持在对照水平。最后，D-色氨酸-6-LH-RH诱导的体外LH释放刺激在雌性垂体中严重受损（p<0.01），但在雄性中仅略有降低。
