RESUMO
In the present work we demonstrated that alkaline dissociation of myocardium using a concentrated 50 per cent solution of KOH is an alternative method capable of producing well preserved cardiac myocytes, which are usefull for morphological studies. Two millimeter thick fragments of mouse, rat, pig and human myocardium, from both atria and ventricles, were immersed in 2 ml of 50 per cent KOH solution (w/v) for 6 to 7 minutes and dissociated with a transfer polyethylene pipette. When the dissociation was complete the suspension was neutralized with 2 ml of a 50 per cent acetic acid solution. After staining with methylene blue or toluidine blue one drop of the cell suspension was examined under light microscope. Althoug several cells were semicontracted of contracted, rat, mouse and pig fresh myocardium showed well preserved myocytes with morphology similar to that reported for these cells after collagenase dissociation. Human ventricular myocytes were frequently fragmented. Whether such effect is caused by autolylic processes or to a pre-agonic degenerative phenomenon is not known. In contrast the human atrial myocardium was easy to dissociate and yield well preserved cells. The results presented here demonstrated tha alkaline dissociation of fresh, unfixed myocardium could be an useful and unexpensive method to study some morphometric characteristics of cardiac myocytes under different experimental conditions.