Cardiac remodeling, apoptosis-related process (Bax, Bcl-2), and their ratio (Bax/Bcl-2) in cardiomyocytes of diabetic rats after combined exercise training and taurine supplementation

Different modalities of exercise improve cardiac function in diabetes. This study evaluated the effects of Taurine supplementation plus endurance and resistance training program on cardiomyocyte apoptosis and myocardial fibrosis in the diabetic rat model. Male Wistar rats were assigned randomly into five groups of eight animals: control group, diabetes mellitus (DM) group, DM + Taurine supplementation group, DM + combined exercise training (endurance and resistance exercise training, ERE), and DM + a combination of Taurine and ERE. Rats were first treated with an intraperitoneal injection (i.p) of nicotinamide (100 mg/kg body weight) dissolved in normal saline for diabetes induction. Twenty minutes later, intraperitoneal injection of STZ (55 mg/kg) dissolved in 0.1 mg citrate buffer was performed (DM group). Rats in the control group were injected with the same volume of citrate buffer. Taurine (100 mg kg−1) was administered by oral gavage six days per week for 8 weeks. In the ERE groups, 1-day resistance training followed 1-day endurance training. The heart tissue of rats was separated to assess the protein expression of Bax and Bcl2 using IHC. There were statistical differences between the Bax protein expression levels in Taurine (p ≤ 0.001), ERE (p ≤ 0.05), and Taurine + ERE (p ≤ 0.001) groups and DM group. Furthermore, Taurine and ERE, alone and in combination, significantly upregulated Bcl2 protein expression compared to the DM group. Bax/Bcl2 ratio was significantly reduced in Taurine + ERE compared to DM, and there was no significant difference between Taurine + ERE and control groups. The percent of collagen deposition was significantly diminished in all groups, especially in the Taurine + EAE group compared to DM (p ≤ 0.001). Based on our results, Taurine and ERE have a synergistic effect on the amelioration of cardiac damages in diabetic rats. Combination treatment compared to separate treatment is more effective in reducing both Bax and collagen deposition in the heart. © 2021, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.