Sodium bicarbonate supplementation prevents cardiac hypertrophy in male rats exposed to high intensity swim exercise via inhibition of lactate dehydrogenase activity

Abstract

Background: Cardiac hypertrophy is linked with ventricular arrhythmia and can be fatal among athletes  engaged in high intensity exercise. This study investigates the effect of sodium bicarbonate on cardiac hypertrophy induced by swim exercise in male Wistar rats.

Methods: Forty male Wistar (100-150 g) randomly divided into 5 groups 1-5 (n =8) were used. Group 1 was the control sedentary animals while groups 2-3 and 4-5 were exercised at low or high intensity, respectively. Groups 1,2 and 4 received distilled water while groups 3 and 5 received sodium bicarbonate (250 mg/kg, p.o) daily. Exercise was carried out by swimming in a temperature regulated water tank 5 days/ week for 8 weeks. The intensity was varied by attaching 5% body weight load to the tail of the high intensity exercise groups while the low intensity groups were unloaded. Body weight was monitored weekly. Blood samples were obtained for plasma lipid profile, C-Reactive Protein (CRP) and Lactate Dehydrogenase (LDH) concentration. Cardiac hypertrophy was determined from the heart weight to tail length (HW:TL) ratio. Data were presented as Mean ± SEM.

Results: Final body weights of all exercised groups were not different when compared with their initial weight. Cholesterol and low-density lipoprotein were decreased in the high intensity exercise group treated with sodium bicarbonate. Triglyceride level was not different across all groups while High-density lipoprotein increased in the low intensity untreated and low intensity treated groups. CRP level was not different across all groups while LDH activity was significantly decreased in the high intensity exercised group treated with sodium bicarbonate. Sodium bicarbonate treatment also caused significant decrease in HW:TL ratio in the treated high intensity exercise group compared with their corresponding untreated group.

Conclusion: Sodium bicarbonate supplementation ameliorated swim exercise-induced cardiac hypertrophy in male Wistar rats through a mechanism that probably involves lactate dehydrogenase activity.