溴氰菊酯对罗非鱼血清中溶菌酶质量浓度及肝脾脏影响

Influences of decamethrin on the concentration of serum lysozyme and the surface changes of liver and spleen in tilapia

随着溴氰菊酯在农业上的广泛应用,其在水环境中的污染机率也在增加。为了研究溴氰菊酯连续暴露对罗非鱼免疫系统的影响。通过测定血清中溶菌酶质量分数,观察罗非鱼（tilapia）肝脾脏的外观变化,以及计算肝脏和脾脏的脏器系数,评价溴氰菊酯连续染毒对罗非鱼的影响。实验设1.0,2.0,3.0,5.0,10.0μg/L5个质量浓度组和空白对照组,同时每组设置一个平行样。试验开始后的第3天,1.0-5.0μg/L质量浓度组的罗非鱼血清中的溶菌酶质量浓度接近或略小于对照组,10.0μg/L质量浓度组与对照组相比下降明显（P〈0.05）,降幅达49.3%。实验7-15d期间,1.0-5.0μg/L质量浓度组罗非鱼血清的溶菌酶质量浓度渐渐升高,高于正常鱼体的质量浓度,最高值可达138.06±2.2μg/mL,为对照组的220.9%（P〈0.05）。10.0μg/L试验组罗非鱼血清中溶菌酶的质量浓度在试验第7天时降至最低,为26.5±1.9μg/mL,为对照组的42.4%,表现出明显的抑制作用（P〈0.01）。随着暴露时间的延长,各试验组在20d时恢复至正常水平,血清中溶菌酶的质量浓度与对照组相比没有明显差异（P〉0.05）;溴氰菊酯染毒第25天时罗非鱼的肝脏和脾脏的脏器系数与对照组相比均未发生明显的差异,罗非鱼的脾脏外观没有发生异常,但肝脏却发生了明显的病变,试验第25d时10.0μg/L质量浓度组罗非鱼肝脏的异常率达66.67%。试验结果表明,溴氰菊酯对罗非鱼血清中溶菌酶的影响是可逆的,对肝脏会造成一定的病理损伤,对脾脏的影响未检出。

The pollution of decamethrin increased with its wide use in agriculture. In order to study the influences on immune system in tilapia by continual exposure to decamethrin of low concentration, The serum lysozyme concentration, surface change of liver and spleen （observed at the end of the study, the 25th day）, and organ coefficients of liver and spleen （calculated at the end of the study, the 25th day） were applied to the analysis the influences of decamethrin （DM） on tilapia by continuous exposure. We set 1.0, 2.0, 3.0, 5.0 and 10.0 μg/L of DM as experimental groups, and a control group. The results showed that DM could influence serum lysozyme concentration of tilapia after continuous exposure. Lysozyme concentrations of 1.0-5.0 μg/L groups were a little below or about equal to control group at the third day, and increased gradually from the 7th day, to the maximum 138.06±2.2μg/mL, which was 2.209 times of the control group. The concentration declined to normal level at the 20th day. While, lysozyme concentrations of 10.0μg/L group declined distinctly at the third day, and declined to the minimum 26.5±1.9pg/mL at the 7th day, which was only 42.4% of the control group. The concentration increased to normal level at the 20th day. There were no obvious difference between lysozyme concentration of experimental groups and control group, from 20th day to 25th day. Furthermore, results of anatomical experiment indicated that at the end of experiment there were no obvious changes between experimental groups＇ and control group＇s organ coefficients of liver and spleen. The appearances of spleens were natural, but there were apparent pathological changes in livers, especially the abnormal rate of 10.0 μg/L group was up to 66.67%. To sum up, the influence of DM to tilapia serum lysozyme is reversible, DM could lead pathology damage to tilapia liver, while the damage to spleen is below detection.