Hymer W C, Grindeland R E, Salada T, Nye P, Grossman E J, Lane P K
Department of Biochemistry and Molecular Biology, Pennsylvania State University 16802, USA.
J Appl Physiol (1985). 1996 Mar;80(3):955-70. doi: 10.1152/jappl.1996.80.3.955.
Space-flown rats show a number of flight-induced changes in the structure and function of pituitary growth hormone (GH) cells after in vitro postflight testing (W. C. Hymen, R. E. Grindeland, I. Krasnov, I, Victorov, K. Motter, P. Mukherjee, K. Shellenberger, and M. Vasques. J. Appl. Physiol. 73, Suppl.: 151S-157S, 1992). To evaluate the possible effects of microgravity on growth hormone (GH) cells themselves, freshly dispersed rat anterior pituitary gland cells were seeded into vials containing serum +/- microM hydrocortisone (HC) before flight. Five different cell preparations were used: the entire mixed-cell population of various hormone-producing cell types, cells of density < 1.071 g/cm3 (band 1), cells of density > 1.071 g/cm3 (band 2), and cells prepared from either the dorsal or ventral part of the gland. Relative to ground control samples, bioactive GH released from dense cells during flight was reduced in HC-free medium but was increased in HC-containing medium. Band 1 and mixed cells usually showed opposite HC-dependent responses. Release of bioactive GH from ventral flight cells was lower; postflight responses to GH-releasing hormone challenge were reduced, and the cytoplasmic area occupied by GH in the dense cells was greater. Collectively, the data show that the chemistry and cellular makeup of the culture system modifies the response of GH cells to microgravity. As such, these cells offer a system to identify gravisensing mechanisms in secretory cells in future microgravity research.
在飞行后进行体外测试后，太空飞行大鼠的垂体生长激素（GH）细胞在结构和功能上出现了许多飞行诱导的变化（W. C. 海曼、R. E. 格林德兰德、I. 克拉斯诺夫、I. 维克托罗夫、K. 莫特、P. 穆克吉、K. 谢伦伯格和M. 瓦斯克斯。《应用生理学杂志》73，增刊：151S - 157S，1992年）。为了评估微重力对生长激素（GH）细胞本身可能产生的影响，在飞行前将新鲜分散的大鼠垂体前叶细胞接种到含有血清±微摩尔氢化可的松（HC）的小瓶中。使用了五种不同的细胞制剂：各种激素产生细胞类型的整个混合细胞群体、密度<1.071 g/cm³（带1）的细胞、密度>1.071 g/cm³（带2）的细胞，以及从腺体的背侧或腹侧制备的细胞。相对于地面对照样本，在无HC培养基中飞行期间致密细胞释放的生物活性GH减少，但在含HC培养基中增加。带1细胞和混合细胞通常表现出相反的HC依赖性反应。腹侧飞行细胞释放的生物活性GH较低；飞行后对生长激素释放激素刺激的反应降低，致密细胞中GH占据的细胞质面积更大。总体而言，数据表明培养系统的化学组成和细胞构成会改变GH细胞对微重力的反应。因此，这些细胞为未来微重力研究中识别分泌细胞的重力感知机制提供了一个系统。
