Wilbur D L, Worthington W C, Markwald R R
Neuroendocrinology. 1975;19(1):12-27. doi: 10.1159/000122421.
The hypophysial portal vessels and anterior pituitary glands of adult male rats were surgically exposed, cannulated and infused for 1 min with saline, growth hormone-releasing factor (GH-RF), and dbcAMP. After cessation of infusion, anterior pituitary glands were collected at 1, 5, 15, 30 or 60 min for electron microscopic and ultrastructural cytochemical examination. Before and after cannulation of a portal vessel a 1-ml sample of blood was collected at 1, 5, 15, 30 or 60 min from the femoral vein for RIA of growth hormone. When viewed ultrastructurally, the initial response following the infusion of GH-RF into a portal vessel was one of granule release. Emiocytic activity was observed at all time intervals studied. This response was followed 30 min later by evidence of increased protein synthesis. Significant increases in plasma GH levels were present at 1, 5, and 15 min following infusion of GH-RF but not at 30 or 60 min. Preliminary analysis of the RIA data suggests that dbcAMP was significantly more potent than GH-RF in elevating radioimmunoassayable plasma GH levels. The results suggest that similar mechanisms of synthesis and release were involved.
对成年雄性大鼠的垂体门脉血管和垂体前叶进行手术暴露、插管，并分别用生理盐水、生长激素释放因子（GH-RF）和二丁酰环磷腺苷（dbcAMP）灌注1分钟。灌注停止后，在1、5、15、30或60分钟时采集垂体前叶，进行电子显微镜和超微结构细胞化学检查。在门静脉插管前后，于1、5、15、30或60分钟时从股静脉采集1毫升血液样本，用于生长激素的放射免疫分析（RIA）。超微结构观察显示，向门静脉灌注GH-RF后的初始反应是颗粒释放。在所有研究的时间间隔内均观察到了胞吐活性。30分钟后出现蛋白质合成增加的迹象。灌注GH-RF后1、5和15分钟时血浆GH水平显著升高，但在30或60分钟时未升高。对RIA数据的初步分析表明，在提高可放射免疫测定的血浆GH水平方面，dbcAMP比GH-RF的作用显著更强。结果表明，两者涉及相似的合成和释放机制。
