Briegleb W, Block I
DFVLR-Institute for Aerospace Medicine, Cologne, FRG.
Adv Space Res. 1986;6(12):15-9. doi: 10.1016/0273-1177(86)90060-8.
When cell physiologists detect gravity related reactions of their objects it is often difficult to decide where the receptors for the observed effects are located. Answering this question is necessary for any further analysis of a detected gravity effect on cells. In previous papers we have discussed direct and indirect gravity effects in relation to the smallest functional units where the primary receptor, which interacts with gravity, is positioned inside and outside of such a unit, respectively. So, in a first approximation we can conclude that in a multicellular aquatic organism, which changes its metabolism in weightlessness, the primary receptors of gravity are located inside the cells of that organism. A special approach is necessary when free living cells, the density of which may be higher than the one of the (liquid) medium, or even cells living on a free surface are observed. In these two cases also indirect effects have to be taken into account, which will be demonstrated with the aid of the slime mold Physarum polycephalum. Additionally the environment of the organisms can be changed directly and indirectly by gravity.
当细胞生理学家检测到其研究对象与重力相关的反应时，往往很难确定所观察到的效应的受体位于何处。对于进一步分析检测到的重力对细胞的影响而言，回答这个问题是必要的。在之前的论文中，我们讨论了直接和间接重力效应，涉及到最小的功能单元，其中与重力相互作用的主要受体分别位于该单元的内部和外部。因此，初步估计我们可以得出结论，在失重状态下改变其新陈代谢的多细胞水生生物中，重力的主要受体位于该生物体的细胞内部。当观察自由生活的细胞（其密度可能高于（液体）介质的密度）甚至生活在自由表面的细胞时，需要一种特殊的方法。在这两种情况下，还必须考虑间接效应，这将借助多头绒泡菌来进行说明。此外，重力可以直接和间接地改变生物体的环境。
