春季温度变化对钉螺酶活性的影响

Influence of temperature change in spring on the activities of enzymes in Oncomelania hupensis

目的 了解春季气候变暖影响钉螺活动性及繁殖能力的作用机理。方法 春季采集的钉螺放入不同温度的恒温培养箱,模拟外界气候变暖。用酶组织化学技术观察不同温度下钉螺中枢神经节、雌雄生殖腺中的一氧化氮合酶(NOS)、琥珀酸脱氢酶(SDH)、乳酸脱氢酶(LDH)及乙酰胆碱脂酶(AchE)的变化。结果 各酶的平均灰度值随着温度升高呈下降趋势。在神经节中25℃组NOS、SDH及AchE的平均灰度值明显低于对照组(P<0.01);25℃组卵集及搴丸组织NOS、SDH及LDH的平均灰度值显著低于对照组;各实验组神经节LDH的平均灰度值与对照组相比无显著性差异(P>0.01)。结论 春季温度变化对钉螺的NOS、SDH、LDH及Ache活性均产生明显影响,温度升高使这些酶活性增强,提高了钉螺的活动性及繁殖力,为进一步研究全球气候变化对血吸虫病传播的影响提供了理论基础。

To understand the mechanism of the global warming impact on the activities and reproductions of Oncomelania hu-pmsis during spring, the snails collected in spring were incubated in different temperatures that mimic the wanning scenario in spring. The changes of nitric oxide synthase (NOS), succmic dehydrogenase (SDH), lactic dehyrogenase (LDH) and acetylcholinesterase (AchE) in the centric ganglions and gonads of O. hupensis were observed by using the enzyme-histochemical techniques. The results showed that the average gray densities of NOS, AchE, SDH and LDH presented a drop trend with increase in temperature, and those of NOS, SDH and AchE in the centric ganglions from 25℃ group and those of NOS, SDH and LDH in ovary and testicle from 25×3 group were all significantly lower than that of the control group;but no difference in the average gray density of LDH in the centric ganglions was found between all the other groups and control group. It concludes that change of temperature in spring impacts obviously to the activities of enzymes in the centric ganglions and gonads of oncomelania snails, because the increase of temperature in spring may trigger the activities of NOS, AchE and SDH to improve the activities and reproduction of oncomelania snails. These results provide the theoretical basis for the study on the impact of global wanning on the transmission of schstosomiasis.