College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, People's Republic of China.
Adv Exp Med Biol. 2013;776:217-29. doi: 10.1007/978-1-4614-6093-0_21.
Taurine is the most abundant free amino acid in the human body and accounts for more than 50% of the total amino acid pool in the mammalian heart. To investigate the preventive effects of taurine on cardiac hypertrophy in rats, myocardial injury was established by hypodermic injection of isoprenaline (ISO) (10 mg/kg d) for 7 days. The preventive effects of taurine (100 mg/kg d, 200 mg/kg d, and 300 mg/kg d, i.p) on heart coefficient; ultrastructure of cardiac muscle; the levels of creatine kinase heart isoenzyme (CK-MB), cAMP, and cGMP; and antioxidant ability were investigated. The results showed that taurine could significantly prevent the increase of heart coefficient induced by ISO. Compared with the model group, 100 mg/kg and 200 mg/kg taurine significantly decrease the levels of cAMP and cGMP, while 300 mg/kg taurine could significantly decrease the levels of cAMP in myocardium, and all the three concentrations of taurine could significantly increase the ratio of cGMP/cAMP. The level of serum CK-MB was significantly increased by ISO; 200 mg/kg taurine could significantly decrease it, but 100 mg/kg and 300 mg/kg taurine had no significant effect. As for the antioxidant ability, ISO administration could significantly increase the myocardial level of MDA but had no significant effects on the myocardial levels of SOD, GSH, GSH-Px, and T-AOC. However, taurine administration could significantly decrease the myocardial level of MDA and increase the levels of GSH and T-AOC compared with the model group. The serum levels of SOD, GSH-Px, GSH, and T-AOC were significantly reduced by ISO administration, but the level of MDA showed no significant changes compared with the control group. Taurine administration could significantly increase the serum levels of SOD, GSH-Px, GSH, and T-AOC and decrease the level of MDA compared with the model group. All the results indicated that 200 mg/kg taurine had better effects. The ultrastructure of cardiomyocytes showed that taurine administration could significantly reverse the injury caused by ISO. In conclusion, the present study demonstrated that taurine could inhibit the injury induced by ISO by increasing myocardial negative inotropic effect and antioxidant ability, decreasing the hypertrophic response to isoproterenol and protecting the integrity of -myocardial ultrastructure, decreasing myocardial leak of CK-MB.
牛磺酸是人体内最丰富的游离氨基酸，占哺乳动物心脏中总氨基酸池的 50%以上。为了研究牛磺酸对大鼠心肌肥厚的预防作用，通过皮下注射异丙肾上腺素（ISO）（10mg/kg·d）建立心肌损伤模型，7 天。牛磺酸（100mg/kg·d、200mg/kg·d 和 300mg/kg·d，ip）对心脏系数的预防作用；心肌超微结构；肌酸激酶同工酶（CK-MB）、cAMP 和 cGMP 水平；以及抗氧化能力进行了研究。结果表明，牛磺酸能显著预防 ISO 诱导的心脏系数增加。与模型组相比，100mg/kg 和 200mg/kg 牛磺酸可显著降低 cAMP 和 cGMP 水平，而 300mg/kg 牛磺酸可显著降低心肌 cAMP 水平，所有三种浓度的牛磺酸均可显著提高 cGMP/cAMP 比值。血清 CK-MB 水平因 ISO 而显著升高；200mg/kg 牛磺酸可显著降低其水平，但 100mg/kg 和 300mg/kg 牛磺酸无明显作用。至于抗氧化能力，ISO 给药可显著增加心肌 MDA 水平，但对心肌 SOD、GSH、GSH-Px 和 T-AOC 水平无显著影响。然而，与模型组相比，牛磺酸给药可显著降低心肌 MDA 水平并增加 GSH 和 T-AOC 水平。血清 SOD、GSH-Px、GSH 和 T-AOC 水平因 ISO 给药而显著降低，但与对照组相比，MDA 水平无显著变化。牛磺酸给药可显著增加血清 SOD、GSH-Px、GSH 和 T-AOC 水平，降低 MDA 水平与模型组相比。所有结果表明 200mg/kg 牛磺酸的效果更好。心肌细胞超微结构显示，牛磺酸给药可显著逆转 ISO 引起的损伤。总之，本研究表明，牛磺酸通过增加心肌负性肌力作用和抗氧化能力，降低对异丙肾上腺素的肥厚反应，保护心肌超微结构的完整性，减少心肌 CK-MB 渗漏，抑制 ISO 引起的损伤。
