Effects of Aerobic Exercise on Energy Metabolism in the Hypertensive Rat Heart

Abstract

AbstractBackground and Purpose. In order to explore the possible effects of physical therapy interventions on patients with hypertension, we evaluated the effects of aerobic exercise training on myocardial energy metabolism in an animal model of hypertension. Subjects. We used 36 female spontaneously hypertensive rats (rats with genetically induced hypertension) and 12 normotensive Wistar-Kyoto rats. Methods. The normotensive rats were sedentary and formed the CONsed group. The spontaneously hypertensive rats were randomly divided into 3 experimental groups (12 rats per group). Hypertensive rats that were sedentary formed the HTNsed group, those that received 8 weeks of exercise training formed the HTN×8 group, and those that received 16 weeks of exercise training formed the HTN×16 group. We measured systolic blood pressure, heart wet weight, maximal activities of cardiac energy metabolism enzymes, glucose transporter content, and total concentrations of protein, glycogen, and triglyceride. Results. Systolic blood pressure was greater than 200 mm Hg in the CONsed group at the time of testing. Exercise training modestly (∼11–18 mm Hg) lowered blood pressure in the HTN×8 and HTN×16 groups. Fatty acid enzyme activity was greater in the CONsed group than in the HTNsed and HTN×8 groups, but activity was roughly equivalent between the CONsed group and the HTN×16 group. Glucose enzyme activity was greater in the HTN×16 group than in the CONsed group and the HTNsed group. Intracellular glycogen concentration was greater in the HTN×8 group than in the HTNsed group. Discussion and Conclusion. Results of this study suggest that aerobic exercise training may help to normalize cardiac energy metabolism in mammals with hypertension.