[Morphofunctional aspects of the experimental effect of hyperbaric oxygenation on the myocardium of the healthy organism].

Changes in the myocardium arter numerous treatments with hyperbaric oxygenation (HBO) (PO2 3 technical atmospheres, time of saturation--45 min) were studied by morphological, histochemical and enzymohistochemical methods in 50 rabbits. Three stages were found to occur in the development of these changes: 1) functional-morphological changes (1--3 seanses of HBO), 2) early morphological changes (4--5 seanses), 3) marked morphological lesions (6--8 seanses). The first three treatments produce reversible changes on the part of metabolic processes (a reduction in the content of glycogen and changes in the activity of oxidoreductases: succinate-, malate- and lactate dehydrogenase). Morphological signs of oxygen toxicity in the form of disorders in hemodynamics and microcirculation, and dystrophy of cardiomyocytes appear after 4 seanses of HBO and increase with further treatment. The experimental data permit to recommend short HBO courses (1--3 seanses) for therapeutic application.