Hymer W C, Salada T, Avery L, Grindeland R E
Department of Biochemistry and Molecular Biology, Pennsylvania State University 16802, USA.
J Appl Physiol (1985). 1996 Mar;80(3):971-80. doi: 10.1152/jappl.1996.80.3.971.
This study was done to evaluate the effects of microgravity on prolactin (PRL) cells of the male rat pituitary gland. We used the identical passive closed-vial cell culture system that was described for the culture of growth hormone cells (W. C. Hymen, R. E. Grindeland, T. Salada, P. Nye, E. Grossman, and P. Lane. J. Appl. Physiol. 80:955-970, 1996). After an 8-day spaceflight, all flight media (containing released PRL), as well as extracts (containing intracellular PRL), contained significantly lower amounts of immunoreactive PRL than their corresponding ground control samples. On the other hand, these same samples, when assessed for their biological activities by two different in vitro lymphocyte assays, yielded disparate results that may reflect posttranslational modifications to the hormone molecule. Other data showed that 1) the apparent molecular weights of released PRL molecules were not altered by microgravity, but 2) the region from which the PRL cells came (dorsal or ventral) made a significant difference in the amount and activity of PRL released from the flight cells. Because there is much current interest in the role that PRL may play in the regulation of the immune system and because changes in both cellular and humoral immunity accompany spaceflight, this study could help define future microgravity research in this area.
本研究旨在评估微重力对雄性大鼠脑垂体催乳素（PRL）细胞的影响。我们使用了与生长激素细胞培养所描述的相同的被动式密闭小瓶细胞培养系统（W. C. 海曼、R. E. 格林德兰德、T. 萨拉达、P. 奈伊、E. 格罗斯曼和P. 莱恩。《应用生理学杂志》80:955 - 970，1996年）。经过8天的太空飞行后，所有飞行培养基（含有释放的PRL）以及提取物（含有细胞内PRL）中免疫反应性PRL的含量均显著低于其相应的地面对照样本。另一方面，当通过两种不同的体外淋巴细胞测定法评估这些相同样本的生物活性时，得出了不同的结果，这可能反映了激素分子的翻译后修饰。其他数据表明：1）释放的PRL分子的表观分子量未因微重力而改变，但2）PRL细胞来源的区域（背侧或腹侧）对飞行细胞释放的PRL的量和活性有显著影响。由于目前人们对PRL在免疫系统调节中可能发挥的作用非常感兴趣，并且由于细胞免疫和体液免疫的变化都伴随着太空飞行，本研究有助于确定该领域未来的微重力研究方向。
