Abstract 203: Angiotensin II Induced ER Stress in the Heart is Attenuated by Exercise

Recent evidence indicates that endoplasmic reticulum (ER) stress plays an important pathophysiological role in a number of chronic diseases including cardiovascular disease. In this study, we demonstrate that ANGII-induced ER stress in the heart is attenuated by exercise. Methods: Male rats were implanted with telemetry probes and trained to do exercise. After collecting baseline blood pressure, hypertension was induced by implanting osmotic minipumps containing ANGII 200ng/kg/min for 42 days or saline. Rats were randomized into sedentary (SED) or exercise trained (ExT). BP and cardiac functions were measured by radiotelemetry and echocardiography. At the end of the study, heart tissues were analyzed for ER stress and hypertrophy markers by real time RT-PCR and Western blotting. Results: are tabulated. The protein expression pattern for Grp78 and CHOP were similar to mRNA. Conclusions: 1. ANGII infusion induces ER stress in the heart and contributes to cardiac hypertrophy. 2. EXT attenuates hypertensive response, cardiac hypertrophy and ER stress. 3. ER stress and ROS dependent mechanism contribute to ANGII induced cardiac hypertrophy and contribute to the development of hypertension.