[Skeletal muscle capillary bed during hypokinesia].

The functioning capillaries (containing red cells) of the gastrocnomius, soleus and tibial muscles as well as biceps femoris were subjected to quantitative histological study in rats exposed to 20-day hypokinesia. During hypokinesia the rats showed atrophy of and reduced blood supply to hind limb muscles as indicated by the decreased number of the functioning capillaries, the number of the capillaries supplying red muscular fiber being lowered in the first turn. The only exception was the soleus muscle where the number of the functioning capillaries remained unchanged, and blood congestion developed. It is suggested that the microcirculatory disorders in the soleus muscle and concomitant tissue hypoxia are responsible for severe dystrophic changes seen in the muscle of the hypokinetic rats.