[Histomorphological changes in the myocardium of experimental animals in long-term exposure to intense industrial noise]

An experiment with male white rats exposed to the influence of industrial noise in an intensity of 95 dbA in the course of 3 consecutive hours daily, for a period of 3 and 5 months resp., was made. The morphological changes in the myocardium of the test animals were studied by applying classical histological and histochemical methods. It was established that the chronic noise causes a spasticatonic state in the vessels. Some hypoxically dependent dystrophic changes occur in the cardiomyocytes. The changes persist for a month upon ceasing of treatment, while during the second month a substituting regeneration develops.