[The effect of space flight factors on the intact and regenerating skeletal muscles of the extremities in newts].

The influence of space flight factors on the structure of two skeletal muscles of the hindlimbs was studied in newts. Degenerative-atrophic changes took place in the both muscles of the flight group animals. Comparative-quantitative analysis of ultrastructural changes of the muscle tissue has shown that after space flight, the rate of structural defects of the muscle was twice that in animals of the synchronous and laboratory control groups. But these changes were reversible: within 10 days, the structure of the muscle fibers was practically normalized. The influence of space flight on repair regeneration of the hindlimb skeletal muscle was also studied: the muscle was minced and placed back in its bed 14 days before the flight. Under these conditions, the repair regeneration of the muscle was not suppressed, but a trend towards its delay was found.