类毒素-A对小鼠脑内钙调信号系统的影响

目的探讨类毒素-A（ANTX-A）诱导的钙调信号系统在中枢神经系统毒性中的作用。方法小鼠腹腔染毒不同剂量ANTX-A1月，对照组给予生理盐水。采用荧光法、比色法测定小鼠大脑内钙离子浓度、钙调神经磷酸酶和A11P酶活性。结果12、5、50和200μg／kg bw ANTX-A的各剂量组小鼠大脑内钙离子浓度明显升高，与对照组相比差异有显著性（P〈0．01）。200μg／kg bw ANTX-A剂量组小鼠大脑内钙调神经磷酸酶活性显著增强。与对照组相比差异有显著性（P〈0．05）。ANTX-A各剂量组小鼠大脑内Na^＋-K^＋-ATP酶活性无明显改变，而50、200μg／kg bw ANTX-A剂量组Ca^2＋-ATP酶活性比对照显著降低（P〈0.05）。结论提示钙调信号系统在类毒素-A的中枢神经毒性中可能有重要调控作用。

Effect of anatoxin-A on calcium-mediate signal system of brain tissue in mice

OBJECTIVE: To explore the mechanism of central neurotoxity induced by anatoxin-A (ANTX-A) from the calcium-mediate signal system. METHODS: Mice were administered by i.p. at different doses of ANTX-A for one month, 0.9% of sodium chloride solution was used as the control. Using fluorescence method and colorimetry method, the intracellular calcium concentration and the activity of calcineurin (CaN, PP2B) and ATPase in brain were determined. RESULTS: Calcium concentrations in brain were increased in 12.5, 50 and 200 microg/kg bw groups compared with the control group, the difference had statistical significance (P < 0.01). The activity of PP2B of brain in 200 microg/kg bw group was enhanced compared with the control group (P < 0.05). In all ANTX-A treated groups, the activity of Na+ -K+ -ATPase of brain in mice had no obvious changes, but the activity of Ca2+ -ATPase in 50 and 200 microg/kg bw groups were significantly reduced compared with the control group ( P < 0.05). CONCLUSION: It is suggested that calcium-mediate signal system could have important regulative action in the central neurotoxity induced by antoxin-A.