锯齿新米虾对Cu^(2+)和毒死蜱毒性的生理响应

Physiological Response of Neocaridina denticulate to the Toxicity of Cu^(2+) and Chlorpyrifos

为研究水生生物对水体中重金属和有机磷农药毒性的生理响应,以锯齿新米虾为试验生物,采用半静止毒性试验方法,分别研究了Cu2+和毒死蜱5 d暴露时间对锯齿新米虾肌肉组织生理指标的影响.结果表明,锯齿新米虾暴露在不同浓度Cu2+和毒死蜱溶液下,随着暴露时间的延长,肌肉组织蛋白浓度均有不同程度的降低.Cu2+溶液较低浓度组(0.086 mg·L-1和0.172 mg·L-1)和毒死蜱较高浓度组(0.006 0μg·L-1和0.012 0μg·L-1)中,总SOD活性表现抑制效应;Cu2+溶液较高浓度组(0.344 mg·L-1和0.688 mg·L-1)表现为"抑制-诱导-抑制"的变化趋势,而毒死蜱较低浓度组(0.001 5μg·L-1和0.003 0μg·L-1)表现为"抑制-诱导"的变化趋势;暴露在Cu2+和毒死蜱溶液下,MDA含量变化相似,且在一定浓度范围内,随着Cu2+和毒死蜱浓度增加,MDA含量呈逐渐上升的趋势,说明Cu2+和毒死蜱加快了锯齿新米虾肌肉组织脂质过氧化作用;ACh E活性在Cu2+和毒死蜱溶液中表现为抑制效应,且在Cu2+和毒死蜱溶液的较高浓度组中,其活性随浓度的增加而呈逐渐降低的趋势,说明Cu2+和毒死蜱对锯齿新米虾肌肉组织的正常生理功能产生了影响,其浓度越高,产生的损伤效应越大.研究表明,鉴于不同浓度的Cu2+和毒死蜱溶液对锯齿新米虾肌肉组织的损伤程度不同,总SOD、MDA和ACh E可以作为评价重金属和有机磷农药对锯齿新米虾急性毒性效应的生理指标.

In order to study the physiological response to heavy metals and organic-phosphorus pesticide toxicity of aquatic organisms,Neocaridina denticulate was used as a test organism to investigate the impact of physiological indices of N. denticulate muscle tissues when they were exposed to Cu2 +and chlorpyrifos for 5 days respectively with the test methods of semi-static toxicity. The results showed that: when exposed to different concentrations of Cu2 +and chlorpyrifos solutions,the protein concentrations in muscle tissues were significantly lower with the extension of time to varying degrees. In the lower concentration groups of Cu2 +( 0. 086 mg·L- 1and 0. 172mg·L- 1) and the higher concentration groups of chlorpyrifos( 0. 006 0 μg·L- 1and 0. 012 0 μg·L- 1),the total SOD activity showed inhibitory effect; the trend of the higher concentration group of Cu2 +( 0. 344 mg·L- 1and 0. 688 mg·L- 1) showed ' inhibitionpromotion-inhibition',however,the lower concentration groups of chlorpyrifos( 0. 001 5 μg·L- 1and 0. 003 0 μg·L- 1) showed the 'inhibition-promotion' changes in trends; MDA contents changed similarly,and within a certain range of concentrations,MDA contents presented a gradually rising trend with increasing Cu2 +and chlorpyrifos concentration,which indicated that Cu2 +and chlorpyrifos accelerated lipid peroxidation in muscle tissues of N. denticulate. In addition,ACh E activity in Cu2 +and chlorpyrifos solutions showed inhibitory effect,and in the solutions with higher concentration of Cu2 +and chlorpyrifos,the activity was gradually decreased with the increase of concentration,indicating that Cu2 +and chlorpyrifoscs impacted the normal physiological functions of N. denticulate,and the higher the concentration,the greater the damage effect. Based on the analysis results,we confirmed that the total SOD,MDA and ACh E played significant roles as physiological indicators in evaluating toxic effect of heavy metals and organic-phosphorus pesticide on N. denticulate.