[Change in the permeability of vessels in the microcirculatory bed of skeletal muscles in conditions of working hyperemia].

Permeability of m. quadriceps femoris and m. gastrocnemius mimicrocirculatory bed of albino rats was studied by fluorescent biomicroscopy at rest and under work hyperemia. Fluorescein-labeled bovine globulin (FBG) was used as an indicator of permeability alteration. Quantitative fluorescent analysis was carried out on a microspectrofluorimeter. In work hypermia the FBG concentration in the muscle exceeded such at rest by 40--45%; this evidenced an increased transendothelial transport. The results of the experiments on the measurement of FBG concentration about a single capillary suggested that the microcirculatory bed permeability increased under work hyperemia.