Protection of Branched-Chain Amino Acids Against Ischemic Myocardial Injury in Rats

The protective effects of Branched-Chain Amino Acids (BCAA) on ischemic myocardium in rats were studied. Thirty Wistar rats (15 female and 15 male) were randomly divided into 3 groups of 10 animals each. Group A: control; group B: isoproternol (ISO); group C: ISO + BCAA. The rats in groups A and B received normal synthetic rat chow while those in group C received BCAA as supplement. After two weeks of dietary treatment, the rats in group A were injected with saline while those of groups B and C were injected with ISO which induced acute ischemic myocardial injury. After 4 days of injections with either saline or ISO, the rats were sacrificed. The activities of lactate dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), alpha-hydroxybutyrate dehydrogenase (alpha-HBDH), creatine kinase (CK), pyruvate kinase (PK) in the serum and in the myocardium, and the concentrations of potassium (K+), magnesium (Mg2+), calcium (Ca2+) in the myocardium were measured. The results showed that the activities of LDH, GOT, alpha-HBDH, CK, PK in the serum and in the myocardium were significantly increased in group B. In addition, the concentrations of Ca2+ in the myocardium were significantly increased. However, the concentrations of Mg2+ in the myocardium were substantially decreased while those of K+ in group B were slightly lowered. In the group C animals both the activities of LDH, alpha-HBDH, PK, CK in the serum and the activities of LDH, GOT, alpha-HBDH, CK in the myocardium were significantly lower than those of the rats in group B, and were not significantly different from those of the control group. More significant was the concentrations of Ca2+ in the myocardium of the rats in group C were comparable to those of the control rats but were significantly lower than those of the rats in group B. It appeared that BCAA was effectively blocking the increase of Ca2+ in the myocardium without raising the level of Mg2+. It was concluded that dietary supplement with BCAA provided some protective effects against ischemic myocardium in rats.