[Ultrastructural analysis of atrial cardiomyocytes of rats exposed to acceleration +5Gz].

Ultrastructural changes in atrial cardiomyocytes of rats chronically exposed to +5 Gz were investigated. Immediately after exposure most cardiomyocytes showed hypertrophic and hyperplastic changes in practically all cell organelles. During a month-long recovery destructive changes that seemed to reflect hypertrophy regression did not return to norm. The above observations concerning changes in the system of atrial hormones together with pertinent data in the literature suggest that a factor produced by the system may be involved in the complex mechanism of acceleration-induced effects on the animal body.