[Effect of cytotoxic hypoxia on the metabolism and ultrastructure of cortical synaptosomes and mitochondria].

The study is concerned with morphochemical changes in the metabolism and ultrastructure of the mitochondria and synaptical endings from the cortex of the hemispheres in rats under the influence of cyanide (7mg/kg) following 30 min, 2 hours and 24 hours after its administration. Subfractions of the light and heavy synaptosomes, as well as in the mitochondria of the cell bodies showed changes in the activity of the enzyme systems (cytochromoxidase, K+, Na+-ATPase and Mg2+-ATPase) and disturbances of the ultrastructure of the eliminated organella. After 24 hours the metabolism normalized, which may be explained by a biochemical brain plasticity at the subcellular level under conditions of histotoxic hypoxia.