Shellenberger K E, Grindeland R E, Hymer W C
Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, USA.
Aviat Space Environ Med. 1998 Jun;69(6 Suppl):A37-44.
While life science data dealing with effects of hypogravity are accumulating, relatively little is known about the effects of hypergravity at the level of either the whole animal or the individual cell. The purpose of this experiment was to compare data collected on cells of anterior pituitaries from animals centrifuged at 2G using an experimental design that was identical to that of a spaceflight experiment performed in 1989.
Centrifugation of the animal at 2G for 14 d alters the function and morphology of cells of the anterior pituitary in subsequent in vitro tests at 1G.
Intact rats were centrifuged at twice Earth's gravity for 14 d in a specially designed animal centrifuge as part of the Cosmos 2G study. This study was designed to replicate a previous spaceflight experiment so that direct comparisons between hyper- (centrifugation, 2G) and hypogravity (spaceflight, 0.001G) could be made. Anterior pituitary cells were then evaluated for cell function and morphology in a variety of post-flight tests.
Growth hormone cells from centrifuged animals released less bioactive, but not immunoreactive, growth hormone (GH) than cells from non-centrifuged animals. This was also true for GH released in response to provocative stimulation by a synthetic peptide (growth hormone releasing hormone, GHRH) that causes GH release after binding to cell membrane receptors. Cell morphology was also different between cells from centrifuged and control animals; cells in the experimental group were smaller and less granulated. However, another type of hormone-producing cell contained in these preparations, viz. prolactin cells, was not affected by centrifugation.
Centrifugation of animals for 14 d alters both the in vitro release of GH and GH cell morphology relative to corresponding controls from non-centrifuged animals. Because prolactin cells are not affected by centrifugation, the response is specific to the GH cell.
虽然关于低重力影响的生命科学数据不断积累，但对于超重力在整个动物或单个细胞水平上的影响却知之甚少。本实验的目的是使用与1989年进行的一项太空飞行实验相同的实验设计，比较从以2G离心的动物垂体前叶细胞收集的数据。
将动物以2G离心14天会改变随后在1G条件下进行的体外测试中垂体前叶细胞的功能和形态。
作为宇宙2G研究的一部分，将完整的大鼠在专门设计的动物离心机中以两倍地球重力离心14天。本研究旨在重复先前的太空飞行实验，以便能够对超重力（离心，2G）和低重力（太空飞行，0.001G）进行直接比较。然后在各种飞行后测试中评估垂体前叶细胞的细胞功能和形态。
与未离心动物的细胞相比，来自离心动物的生长激素细胞释放的生物活性生长激素（GH）较少，但免疫反应性生长激素并不少。对于由合成肽（生长激素释放激素，GHRH）刺激释放的GH也是如此，该合成肽在与细胞膜受体结合后会导致GH释放。离心动物和对照动物的细胞之间的细胞形态也有所不同；实验组的细胞较小且颗粒较少。然而，这些制剂中含有的另一种产生激素的细胞，即催乳素细胞，不受离心影响。
与未离心动物的相应对照相比，将动物离心14天会改变GH的体外释放和GH细胞形态。由于催乳素细胞不受离心影响，这种反应是GH细胞特有的。
