[Contractile properties of muscle fibers in rats after long-term exposure to acceleration + 2Gx].

The effect of 21-day exposure to +2 Gx and +1.1 Gx on the contractile properties of different muscle groups of rat fore- and hindlimbs was examined, using glycerinated myofibers in the ATP + Ca2+ solution. It was found that the isometric contraction strength and velocity increased, the performance of the postural extensors also grew: that of the soleus m. in the +2 Gx rats and that of the triceps brachii m. in the +2 Gx and +1.1 Gx rats. The contractile changes of the flexors of fore- and hindlimbs were insignificant and sometimes oppositely directed. The different responses of the muscles to acceleration were associated with the differences in their function, metabolism and biomechanics.