THE ACTION OF DIAZEPAM ON NOISE-INDUCED ALTERATIONS IN RAT ATRIAL TISSUE - AN ULTRASTRUCTURAL-STUDY

The effects of pretreatment with a benzodiazepine, diazepam, on the at rial tissue of rats exposed to noise were studied by means of electron microscopy. Examination of ultrathin sections showed that acute stres s caused swelling of mitochondria with cristolysis and matrix dissolut ion. In diazepam-pretreated and noise-exposed animals atrial cardiomyo cytes did not reveal noteworthy changes in comparison with controls an d the majority of mitochondria were well preserved. Present findings i ndicate that diazepam is able to exert a protective action on cardiac alterations due to noise exposure, especially at the mitochondrial lev el.