【摘要】 采用浸浴法研究了镉(Cd2+)胁迫下,添加不同浓度低分子量壳聚糖(LMWC)对长江华溪蟹(Sinopotamon yangtsekiense)超氧阴离子(O2·)、羟自由基(·OH)和过氧化氢(H2O2)三种氧自由基的影响,并初步探讨了LMWC的作用机制。实验设置5个LMWC与Cd2+联合作用组(5、10、20、40和80mg/L)、1个Cd2+对照组(58mg/L)和1个空白对照组,分别在96h后测定鳃、肝胰腺和心脏的抗O2·能力、抑制·OH能力和H2O2含量。结果显示,Cd2+可以诱导蟹体产生大量的氧自由基,并导致机体的抗氧化能力降低,LMWC的加入可以有效抑制Cd2+引起的氧化损伤,其抑制作用随LMWC浓度的增大逐渐增强。LMWC浓度达到40mg/L和80mg/L时抑制作用显著。LMWC对镉染毒引起蟹体内过量氧自由基有一定的清除作用。--更多还原

【Abstract】 The protective effects of variant concentrations of low molecular weight chitosan (LMWC) (5, 10, 20, 40 and 80 mg/L) on cadmium-induced oxygen free radicals and the possible mechanisms were investigated in freshwater crab Sinopotamon yangtsekiense. The oxygen free radicals included superoxide anion radical (O·2), hydroxyl radical (· OH) and hydrogen peroxide (H2O2) in hepatopancreas, gill and heart. The crabs were exposed to cadmium (Cd2+) (58 mg/L) and LMWC together for 96 hours. The results showed that Cd2+ could increase the production of oxygen free radicals and decrease the oxidative damage obviously. LMWC at the high dose (40 mg/L and 80 mg/L) could remarkably inhibit the production of oxygen free radicals and improve the state of oxidative stress. Furthermore, the dose-effect relationship is significant. According to these results, it is concluded that LMWC has certain scavenging effects on the oxygen free radicals induced by cadmium.更多还原