Antakly T, Pelletier G, Zeytinoglu F, Labrie F
J Cell Biol. 1980 Aug;86(2):377-87. doi: 10.1083/jcb.86.2.377.
The secretion of prolactin in cultured pituitary cells was studied in correlation with the cellular changes induced by stimulatory or inhibitory agents. The techniques used in this study were: radioimmunoassay, immunocytochemistry, scanning (SEM) as well as transmission (TEM) electron microscopy. Prolactin secretion was stimulated by 17 beta-estradiol (10 nM) as well as thyrotropin-releasing hormone (TRH) (3 nM) and inhibited by 2-Br-alpha-ergocryptine (CB-154) (1 muM). The total prolactin (release and cell content) increased between 2 and 8 d of estradiol treatment, indicating an increase of both synthesis and release of prolactin. This finding was in agreement with TEM observations because, in estradiol-treated prolactin cells, the Golgi saccules were distended and Golgi elements were increased, thus indicating increased synthetic activity of these cells. The addition of TRH over a 4-h period resulted in a significant degranulation of prolactin cells. In contrast, prolactin secretory granules became accumulated in the cells after CB-154 treatment for a period ranging from 4 to 24 h. In agreement, light microscope immunocytochemistry showed an increased reaction for prolactin after short-term (< 24 h) incubation with CB-154. Because prolactin cells represent approximately 70% of the glandular cell population as revealed by immunocytochemistry, it was then possible to observe the changes of cell surface by SEM. In most cells, estradiol and TRH led to an increase in the number and prominence of microvilli and blebs, whereas CB-154 treatment resulted in a slightly decreased number of microvilli and an increased occurrence of membrane foldings. This report thus provides morphological evidence for the stimulatory effects of estradiol and TRH, and the inhibitory effects of CB-154 on prolactin secretion in pituitary cells in primary culture. These data, moreover, show that acute changes in secretory activity of prolactin-secreting cells are accompanied by marked changes of their morphological characteristics.
本研究探讨了培养的垂体细胞中催乳素的分泌与刺激或抑制因子诱导的细胞变化之间的关系。本研究采用的技术包括：放射免疫分析、免疫细胞化学、扫描电子显微镜（SEM）以及透射电子显微镜（TEM）。17β-雌二醇（10 nM）和促甲状腺激素释放激素（TRH）（3 nM）可刺激催乳素分泌，而2-溴-α-麦角隐亭（CB-154）（1 μM）则抑制催乳素分泌。在雌二醇处理的2至8天内，总催乳素（释放量和细胞内含量）增加，表明催乳素的合成和释放均增加。这一发现与透射电子显微镜观察结果一致，因为在经雌二醇处理的催乳素细胞中，高尔基囊泡扩张，高尔基元件增多，从而表明这些细胞的合成活性增强。在4小时内添加TRH会导致催乳素细胞显著脱颗粒。相反，在CB-154处理4至24小时后，催乳素分泌颗粒在细胞内积累。同样，光学显微镜免疫细胞化学显示，与CB-154短期（<24小时）孵育后，催乳素反应增强。免疫细胞化学显示催乳素细胞约占腺细胞群体的70%，因此可以通过扫描电子显微镜观察细胞表面的变化。在大多数细胞中，雌二醇和TRH导致微绒毛和泡状突起的数量和突出程度增加，而CB-154处理则导致微绒毛数量略有减少，膜折叠现象增多。因此，本报告提供了形态学证据，证明雌二醇和TRH对原代培养垂体细胞中催乳素分泌具有刺激作用，而CB-154具有抑制作用。此外，这些数据表明，催乳素分泌细胞分泌活性的急性变化伴随着其形态特征的显著变化。
