久效磷对美国红鱼鳃Na^＋／K^＋-ATP酶活性和超显微结构的影响

经不同试验浓度的久效磷(0．25、0．5、1．0和2．0mg·L^-1)处理美国红鱼4d后，分别对鱼鳃Na^+／K^+—ATP酶活性和氯细胞密度进行了测定和计数，并观察了鱼鳃组织显微结构和超微结构的变化。结果表明，低浓度久效磷(0．25mg·L^-1)处理可以诱导鱼鳃氯细胞大量增生，Na^+／K^+—ATP酶活性增强，随着试验浓度的增加，久效磷对鳃组织的损伤越来越重，Na^+／K^+—ATP酶活性逐渐降低；久效磷对鱼鳃显微结构的损伤表现为鳃小片上皮细胞水肿、脱离。鳃小片基部粘连。鳃小片上皮细胞角质化；超微结构变化主要为内质网、线粒体、微小管和核膜的水肿及部分溶解，这种损伤表现为由细胞膜到细胞核的动态过程。

Effect of monocrotophos on Na+ /K+ -ATPase activity and ultramicrostructure of Sciaenops oellatus branchiae

The exposure of Sciaenops ocellatus to monocrotophos at its concentration of 0.25, 0.5, 1.0 or 2.0 mg L-1 for 4 days demonstrated that under the stress of low concentration (0.25 mg.L-1) monocrotophos, the chloride cells of branchiae proliferated, accompanied with the increase of Na+/K(+)-ATPase activity, while under high concentrations of monocrotophos, the damage of gill was much heavier, and the Na+/K(+)-ATPase activity also decreased. The damage in gill under sublethal monocrotophos exposure included hypertrophy and edema, and thus, the lamellar epithelium became thick and lifting, and the lamellae were bulbing or fusing. The ultramicrostructural changes of the gill of the exposure fish were the swollen and even rupture of rER, mitochondria, microtubule and nuclear membrane.