Sancho E, Fernández-Vega C, Ferrando M D, Andreu-Moliner E
Department Biology (Animal Physiology), Faculty of Sciences, Autonomous University of Madrid, Madrid, Spain.
Ecotoxicol Environ Saf. 2003 Nov;56(3):434-41. doi: 10.1016/s0147-6513(03)00077-0.
European eels (Anguilla anguilla) were exposed to a sublethal thiobencarb concentration of 0.22 mg/L in a flow-through system for 96 h. Mg(2+) and Na(+)-K(+) adenosine triphosphatase (ATPase) activities were evaluated in gill and muscle tissues at 2, 12, 24, 48, 72, and 96 h of thiobencarb exposure. Gill ATPase activities were rapidly inhibited from 2h of contact onward. Highest inhibition was registered for Na(+), K(+)-ATPase (85%) from 2 to 12h. Both Mg(2+) and total ATPase were inhibited (>73%) during the first hours of toxicant exposure. At the end of the exposure period (96 h) ATPase activities were still different from those of the controls (>50%). Significant inhibition was detected in Na(+), K(+)-ATPase activity (80%) in muscle tissue after 2h and it was maintained over the entire exposure time. However, Mg(2+)-ATPase and total ATPase showed only perturbations after 2 h of exposure. Eels were exposed to 0.22 mg/L of thiobencarb for 96 h and then a recovery period in herbicide-free water was allowed for 192 h. Gill and muscle samples were removed at 8, 24, 72, 96, 144, and 192 h and ATPase activity was evaluated. Following 144 h of recovery, Mg(2+)- and Na(+), K(+)-ATPase activities, as well as total ATPase activity, in gills of those animals previously exposed to 0.22 mg/L of thiobencarb were still significantly different compared to controls. Thiobencarb seems to act to alter the ionic profiles. Since ion-dependent ATPases are known to regulate the influx and efflux of ions across the membrane to maintain the physiological requirements of the cells, the inhibition of Na(+), K(+)-ATPase probably induced osmoregulatory perturbations. On the other hand, thiobencarb exposure causes increases in the muscle water content of A. anguilla. The results indicated that water content increased significantly (>100% higher than the controls) during the first 24 h of exposure.
在流通系统中，将欧洲鳗鲡（Anguilla anguilla）暴露于亚致死浓度（0.22毫克/升）的杀草丹中96小时。在接触杀草丹2、12、24、48、72和96小时后，评估鳃和肌肉组织中的镁离子（Mg(2+)）以及钠钾腺苷三磷酸酶（Na(+)-K(+) ATPase）的活性。从接触2小时起，鳃ATP酶活性迅速受到抑制。在2至12小时期间，钠钾ATP酶（Na(+), K(+)-ATPase）的抑制率最高（85%）。在接触毒物的最初几个小时内，镁离子（Mg(2+)）和总ATP酶均受到抑制（>73%）。在暴露期结束时（96小时），ATP酶活性仍与对照组不同（>50%）。在肌肉组织中，接触2小时后即检测到钠钾ATP酶（Na(+), K(+)-ATPase）活性受到显著抑制（80%），且在整个暴露期间一直保持。然而，镁离子ATP酶（Mg(2+)-ATPase）和总ATP酶仅在暴露2小时后出现扰动。将鳗鲡暴露于0.22毫克/升的杀草丹中96小时，然后在无除草剂的水中恢复192小时。在恢复8、24、72、96、144和192小时后采集鳃和肌肉样本，并评估ATP酶活性。在恢复144小时后，先前暴露于0.22毫克/升杀草丹的动物鳃中的镁离子（Mg(2+)）、钠钾ATP酶（Na(+), K(+)-ATPase）活性以及总ATP酶活性与对照组相比仍有显著差异。杀草丹似乎会改变离子分布。由于离子依赖性ATP酶已知可调节离子跨膜的流入和流出，以维持细胞的生理需求，钠钾ATP酶（Na(+), K(+)-ATPase）的抑制可能会导致渗透调节紊乱。另一方面，接触杀草丹会导致欧洲鳗鲡肌肉含水量增加。结果表明，在暴露的前24小时内，含水量显著增加（比对照组高出>100%）。
