Vasques M, Lang C, Grindeland R E, Roy R R, Daunton N, Bigbee A J, Wade C E
Life Sciences Division, NASA-Ames Research Center, Moffett Field, CA, USA.
Aviat Space Environ Med. 1998 Jun;69(6 Suppl):A2-8.
Centrifugation has been proposed to be one possible countermeasure for the skeletal muscle, organ, hormonal, and plasma chemistry adaptations associated with chronic unloading (e.g., during spaceflight).
Our hypothesis was that there would be a continuum of physiological and morphological responses from zero gravity to hypergravity.
Adult male rats were centrifuged continuously at 2G for 14 d and the weights of limb muscles and organs, and the levels of plasma constituents were compared with the same measurements from rats flown on a 14-d spaceflight (Cosmos 2044).
Mean body weights of centrifuge rats did not change, whereas age-matched controls grew 21%. There was a sparing of muscle protein in the centrifuge rats; the absolute weights of predominantly slow muscles in the hindlimb were maintained and the relative weights (expressed relative to body weight and as a percent difference from control) of almost all muscles studied were larger than control. In contrast, spaceflight resulted in a decrease in the relative weights of most extensor, but not flexor, hindlimb muscles studied. Relative organ weights, in general, were elevated in centrifuge rats compared with control rats. Relative organ weights in flight rats were similar to control, except for a decrease in testes weight. Plasma thyroxine and testosterone levels were significantly reduced following flight, whereas only thyroxine was decreased after centrifugation. Centrifugation resulted in a decrease in most other plasma chemistry measurements, whereas flight rats showed no change or an elevation in these measures.
These data indicate that the physiological responses to micro- and hypergravity are often in the opposite direction, suggesting that in general there is a continuum of physiological and morphological effects from microgravity to 1G to hypergravity. These data further suggest that the imposition of hypergravity conditions on animals that are in a microgravity environment may have a beneficial effect in maintaining some physiological systems at or near control levels.
离心法已被提议作为一种可能的对策，用于应对与长期失重（如在太空飞行期间）相关的骨骼肌、器官、激素和血浆化学成分的适应性变化。
我们的假设是，从失重到超重会有一系列连续的生理和形态学反应。
成年雄性大鼠连续14天接受2G离心，将其肢体肌肉和器官重量以及血浆成分水平与在14天太空飞行（宇宙2044号）中的大鼠的相同测量值进行比较。
离心大鼠的平均体重没有变化，而年龄匹配的对照组体重增长了21%。离心大鼠的肌肉蛋白质得到了保留；后肢主要慢肌的绝对重量得以维持，几乎所有研究的肌肉的相对重量（相对于体重表示，并作为与对照组的百分比差异）均大于对照组。相比之下，太空飞行导致所研究的大多数后肢伸肌而非屈肌的相对重量下降。一般而言，离心大鼠的相对器官重量高于对照大鼠。飞行大鼠的相对器官重量与对照相似，但睾丸重量下降。飞行后血浆甲状腺素和睾酮水平显著降低，而离心后仅甲状腺素水平下降。离心导致大多数其他血浆化学成分测量值下降，而飞行大鼠在这些测量中没有变化或有所升高。
这些数据表明，对微重力和超重的生理反应通常方向相反，这表明一般来说，从微重力到1G再到超重存在一系列连续的生理和形态学效应。这些数据进一步表明，对处于微重力环境中的动物施加超重条件可能对将某些生理系统维持在或接近对照水平具有有益作用。
