GENDER DIFFERENCE IN NOISE STRESS-INDUCED ULTRASTRUCTURAL-CHANGES IN RAT MYOCARDIUM

Male and female rats were exposed to noise 6 h daily for 7 days runnin g and the effect of stress was evaluated both on myocardium ultrastruc ture and plasma corticosterone level. Both sexes showed subcellular al terations of cardiomyocytes; mitochondria, in particular, which result ed the most affected organelles, exhibited diluted matrix and cristoly sis; in some areas, the sarcoplasmic reticulum appeared vesiculated. Q uantitative analysis of altered mitochondria revealed that atrial myoc ardium was more affected in males than in females. Moreover, corticost erone plasma assay showed, in exposed animals, a growing increase with out significant gender differences. The present findings suggest a mor e marked involvement of male sex when challenged with noise stressor.