感染后家蝇幼虫离体血细胞及培养上清中2种酶活性的变化

目的]探讨大肠杆菌感染后家蝇三龄幼虫血清中酸性磷酸酶（ACP）、过氧化物酶（POD）活性升高的机制。方法]家蝇三龄幼虫离体培养血细胞中加入大肠杆菌菌液,于离体培养后48、1、2、16 h测定血细胞及培养上清中ACP、POD活性的变化。结果]（1）大肠杆菌感染后各时间组培养上清和离体血细胞中ACP活性显著高于CK（P〈0.01）。其中培养上清和离体血细胞中ACP活性分别在感染12 h8、h达高峰,然后逐渐下降。（2）大肠杆菌感染后各时间组培养上清和离体血细胞中POD活性显著高于CK（P〈0.01）。其中培养上清和离体血细胞中POD活性分别在感染12 h4、h达高峰,然后逐渐下降。结论]家蝇幼虫血细胞脱颗粒释放ACP、POD是引起感染后血清中这2种酶活性升高的主要机制。

Change of Two Enzyme Activity in Isolated Hemocytes and Culture Supernatant of the Musca domestica Larva Infected with Escherichia coli

Objective] The aim was to explore the mechanism of increase in activity of acid phosphatase(ACP) and peroxidase(POD) in serum of the Musca domestica larva infected with Escherichia coli.Method] After E.coli were injected into isolated cultured hemocytes of the 3rd stage larva of Musca domestica,the change of activity of ACP and POD in isolated hemocytes and culture supernatant was determined at 4 h,8 h,12 h and 16 h after culturing in vitro.Result](1) The activity of ACP in culture supernatant and isolated hemocytes was much higher than that in the control group at 4 h,8 h,12 h and 16h after infection(P<0.01),reached a peak in culture supernatant and isolated hemocytes at 12 h and 8h after infection,respectively,and gradually decreased.(2)The activity of POD in culture supernatant and isolated hemocytes was much higher than that in the control group at 4 h,8 h,12 h and 16h after infection(P<0.01),reached a peak in culture supernatant and isolated hemocytes at 12 h and 4 h after infection,respectively,and gradually decreased.Conclusion] The main mechanism of increase in two enzyme activity after infection was that hemocytes of Musca domestica larva released ACP and POD by degranulation.