镉对黄颡鱼鳃线粒体结构和能量代谢的影响

采用室内模拟方法，研究了重金属镉对黄颡鱼[Pelteobagrus fulvidraco (Richardson)]鳃线粒体结构和能量代谢的影响及其作用机理.结果表明，50 μg·L^-1组黄颡鱼鳃线粒体结构未受损，且各项测定指标与对照组无显著差异(P＞0.05)；500 μg·L^-1组黄颡鱼鳃线粒体严重受损，除LD、MDA、ADP、AMP和血浆K⁺含量显著高于对照组外，其余检测指标均显著低于对照组(P＜0.05).高浓度镉短期暴露将降低鱼鳃线粒体SOD活性而导致线粒体氧化损伤,同时抑制PFK和ATP酶活性, 影响鳃的能量供应和利用，最终降低鳃血浆渗透压和离子浓度调节能力可能是其毒性机理之一.

Effects of cadmium on mitochondrion structure and energy metabolism of Pelteobagrus fulvidraco gill

To explore the effects and possible mechanisms of environmental cadmium (Cd) on the mitochondrion structure and cellular energy metabolism of Pelteobagrus fulvidraco gill, specimens of P. fulvidraco were exposed to different Cd concentrations (0, 50, 500 microg x L(-1) freshwater) for 7 days. The results showed that when exposed to 50 microg Cd x L(-1), the mitochondrion structure of P. fulvidraco was intact, and no significant differences were observed in all test biochemical indicators, compared with the control (P > 0.05). But, when exposed to 500 microg Cd x L(-1), mitochondria were damaged severely, and except that the LD, MDA, ADP and AMP contents in mitochondria as well as the K+ concentration in plasma were significantly higher than the control, all other test biochemical indicators were decreased significantly (P < 0.05). It was suggested that short-term exposure to higher concentrations of Cd would lead to the obstruction of energy supply and utilization due to the inhibition of PFK and ATPase activity and the oxidative damage of mitochondria resulted from the decrease of SOD activity, and decrease the ability of gills in regulating plasma ion composition and osmolality, which could be one of the possible mechanisms for Cd toxicity.