牛磺酸对虎纹蛙非特异性免疫及血清氧化还原状态的影响

为探讨牛磺酸在无尾两栖类免疫调节和抗氧化能力方面的功能和作用,通过灌胃方式研究了不同浓度牛磺酸对虎纹蛙(Hoplobatrachus rugulosus)脾巨噬细胞呼吸爆发、外周血吞噬活力、胃溶菌酶活力以及血清丙二醛(MDA)和谷胱甘肽(GSH)含量的影响。结果表明:连续7 d的牛磺酸灌胃可显著提高脾巨噬细胞的呼吸爆发强度和外周血细胞的吞噬活力并呈现出明显的剂量效应。当灌胃浓度达到0.8 g/L时两者均达到峰值,但高于0.8 g/L时则表现出条件毒性。胃溶菌酶活力在各浓度下无明显变化。此外,血清MDA含量随牛磺酸浓度的升高而降低,GSH含量在一定的浓度范围内呈现出明显的剂量效应,在1 g/L时达到峰值。研究结果证明牛磺酸可以明显提高虎纹蛙的非特异性免疫功能和机体氧化防御能力,但摄入过量则表现出条件毒性。基于上述指标的评估,虎纹蛙对牛磺酸的适宜需求量按体重计算约为16~20 mg/kg。

Effects of Taurine on Non-specific Immunity and Serum Redox State in Hoplobatrachus rugulosus

The aim of this research is to explore the role of taurine in immunoregulation and oxidation defense in amphibians.The individuals of Hoplobatrachus rugulosus were administered with different dosages of taurine solution by gastric perfusion for 7 days.After that,respiratory burst of spleen macrophages,peripheral blood phagocytic activity and gastric lysozyme activity and concentrations of serum malonaldehyde (MDA) and glutathione (GSH) were determined.Statistical tests were performed using SPSS 17.0.Data are expressed as Mean ± Standard error of the mean (S.E.M.).To determine the existence of statistical differences between different concentrations,one-way ANOVA was used,followed by LSD test (with a degree of significance of P ＜ 0.05).The results indicated that taurine increased both intensity of splenic macrophage respiratory burst and peripheral blood phagocytic activity in a dose-dependent manner,reaching to peak at 0.8 g/L.However,emergence of conditional toxicity was observed when the concentration of taurine exceeded 0.8 g/L (Fig.la and b).No significant change of gastric lysozyme activity was found among different taurine concentrations (Fig.lc).Serum MDA content was decreased with increasing taurine concentrations,while serum GSH was increased in a dosage-dependent mannerin a certain concentration range (peak reached at 1 g/L) and the emergence of conditional toxicity was observed when the taurine concentration exceeded 1 g/L (Fig.2a and b).Overall,taurine can markedly improve the immune function and increase antioxidant ability of the H.rugulosus within a certain concentration range and the best dosage to satisfy the nutritional requirement is about 16-20 mg/kg body weight basing on our investigations.