低浓度头孢类抗生素暴露对嗜热四膜虫超氧化物歧化酶和乳酸脱氢酶活力的影响

Effects of environmental relevant concentration exposure to cephalosporin antibiotics on activity of superoxide dismutase and lactic dehydrogenase of Tetrahymena thermophila

目的研究头孢类抗生素在环境相关浓度水平对嗜热四膜虫超氧化物歧化酶(SOD)和乳酸脱氢酶(LDH)活力的影响。方法将处于对数生长期的嗜热四膜虫分别暴露于不同浓度的头孢氨苄和头孢拉定溶液,终浓度分别为0(对照)、0.05、1.0、1 000.0μg/L。30℃暴露24 h后,测定嗜热四膜虫SOD和LDH的活力。结果与对照组比较,各浓度头孢氨苄暴露组嗜热四膜虫SOD活力均较高,差异有统计学意义(P<0.05);而1.0和1 000.0μg/L头孢氨苄暴露组嗜热四膜虫LDH活力显著降低,差异均有统计学意义(P<0.01)。与对照组比较,0.05μg/L头孢拉定暴露组嗜热四膜虫SOD活力较低,1.0和1 000.0μg/L头孢拉定暴露组嗜热四膜虫SOD活力较高,差异均有统计学意义(P<0.05);仅1.0μg/L头孢拉定暴露组嗜热四膜虫LDH活力显著降低,差异有统计学意义(P<0.01)。结论环境相关浓度的头孢氨苄和头孢拉定对嗜热四膜虫酶活力产生一定影响。

Objective To study the effects of two main cephalosporin antibiotics （cephalexin and cefradine） on Tetrahymena thermophila at the environmental relevant concentration through testing the changes of the activities of superoxide dismutase （SOD） and lactic dehydrogenase （LDH）. Methods Tetrahymena thermophila, which were in a logarithmic growth period, were exposed to different concentrations of cephalexin and cefradine for 24 h at 30 ℃. The final concentrations of the two drugs were 0 （control）, 0.05, 1.0, and 1 000.0 μg/L. Then, the activities of SOD and LDH in Tetrahymena thermophila were tested. Results Compared with the control group, SOD activities in Tetrahymena thermophila in every cephalexin exposuure group was significantly increased （P〈0.05）; However, LDH activities in Tetrahymena thermophila in 1.0 and 1 000.0 μg/L cephalexin groups were reduced （P〈0.01）. Compared with control group, SOD activity in Tetrahymena thermophila in 0.05 μg/L cefradine exposure group was reduced, but SOD activities in Tetrahymena thermophila in the 1.0 and 1 000.0μg/L cefradine groups were significantly increased（P〈0.05）; LDH activity was reduced only in 1.0 μg/L cefradine group（P〈0.01 ）. Conclusion Cephalexin and cefradine may have adverse effects on Tetrahymena thermophila at the environmental relevant concentration.