RESUMEN
Cardiac arrhythmia affects ~ 6% in those over 65 years of age (old), but with 0.2% occurrence in those of 45 years and below (young). Arrhythmia can result from dysregulation of the cardiac impulse generation and its conduction. Connexin proteins are responsible for cardiac impulse conduction, and phosphorylation of connexin 43 determines its functional ability. In this study, Phosphorylated connexin 43, density and expression were assessed in ventricular tissues from young (6 months old) and old (24 monthsold) Wister rats, using the techniques of western blot and immunohistochemistry. Results show that phosphorylated Cx43 in the left ventricle of 24 months old rats significantly declined (P=0.04 & 0.01) by method of western blot and immunohistochemistry respectively, but did not differ in the right ventricle. The left ventricle is known to be responsible for cardiac output. This data suggest an age-associated decline in the expression of phosphorylated connexin 43 in the left ventricle, which may play a significant role in the development of cardiac arrhythmia in the elderly.