亚硝酸盐暴露对红耳龟与中华条颈龟幼体的慢性毒性效应

Effects of Chronic Ambient Nitrite Exposure in Trachemys scripta elegans and Mauremys sinensis

对比研究了亚硝酸盐4个浓度NaNO2(0、100、200、500mg/L)暴露对红耳龟(平均体重13.89g±1.67g,n=224)和中华条颈龟(平均体重13.12g±1.83g,n=236)机体慢性毒性效应的影响。结果表明,红耳龟各暴露组肠中亚硝酸盐含量均低于中华条颈龟,且胁迫20d时差异极显著(P<0.01);胁迫20d、40d时红耳龟肝中亚硝酸盐含量高于中华条颈龟,但60d时却明显低于中华条颈龟。同时,红耳龟肝肠中超氧化物歧化酶(SOD)活性始终高于中华条颈龟,丙二醛(MDA)含量始终低于中华条颈龟;红耳龟暴露40d后肝中SOD活性增强,MDA含量减少,而中华条颈龟SOD活性依旧降低,MDA含量继续增加,这说明红耳龟比中华条颈龟具有更强的适应力和耐受力。本研究为红耳龟生态入侵机理研究提供了生理学依据,为保护物种多样性提供了理论依据。

In order to determine the effects of ambient nitrite exposure on turtles,224 juvenile Trachemys scripta elegans（weight=13.89 g±1.67 g）and 236 juvenile Mauremys sinensis（weight=13.12 g±1.83 g）were randomly divided into four groups（[NO2-] 0,100,200,500 mg/L）to study the effects of chronic ambient nitrite exposure between the two species.The results showed that：nitrite concentration in the intestine was lower in T.s.elegans than in M.sinensis,and it＇s significantly different when exposed 20 d（P〈0.01）;nitrite concentration in the liver of T.s.elegans was higher at 20 d and 40 d exposure,but lower at 60 d exposure.Superoxide dismutase（SOD）activity in the liver and intestine of T.s.elegans were higher than those in M.sinensis,however malonic dialdehyde（MDA）levels were lower.After being exposed for 40 d,SOD activity increased and MDA levels decreased in the liver and intestine of T.s.elegans with time,but for M.sinensis,SOD activity still decreased and MDA levels increased.Therefore,these results indicated that adaptation and the anti-stress ability in T.s.elegans were stronger than in M.sinensis.