Exercise training attenuates apoptosis in the spontaneously hypertensive rat

Cardiomyocyte loss via apoptosis has been centrally implicated in the progression of hypertension to heart failure. However, limited data exist regarding the impact of exercise training on apoptosis in hypertension. Therefore, we tested the hypothesis that exercise training reduces apoptosis in the hypertensive myocardium. METHODS: Twenty‐five, 16‐week old, female, Wistar‐Kyoto (WKY) and spontaneously hypertensive rats (SHR) were placed into sedentary (WKY‐SED; SHR‐SED) or treadmill trained (WKY‐TRD; SHR‐TRD) groups. Following 12 weeks of exercise (5 days/wk, 60 min/d at 20–25 m/min) hearts were isolated, fixed and embedded in paraffin. Transverse sections were analyzed via TUNEL. Snap frozen sections of the left ventricle (LV) were assayed for western blotting. RESULTS: TUNEL positive cardiomyocyte nuclei were increased in SHR‐SED compared to WKY‐SED (P<0.05), an effect that was attenuated by exercise training (SHR‐TRD). This increase in apoptosis was associated with a decrease in inhibitors of apoptosis (C‐IAP and X‐IAP) and a decrease in Bad phosphorylation at serine 112 in the SHR‐SED vs. WKY‐SED. Exercise training increased C‐IAP and X‐IAP expression as well as Bad phosphorylation. CONCLUSIONS: Myocardial apoptosis is increased with hypertension and heterogeneously dispersed across the LV. Exercise training attenuates apoptosis in the SHR model by increasing anti‐apoptotic markers.