盐度对大鳞副泥鳅抗氧化酶及组织结构的影响

为研究盐度对大鳞副泥鳅（Paramisgurnusdabryanus）Na+-K+-ATP酶（NKA）、抗氧化酶活性及组织结构的影响，试验设置4、8、12共3个盐度组和一个淡水组（对照），以全长（17.60±0.69）cm，体质量（35.51±5.30）g的大鳞副泥鳅进行14 d胁迫试验。结果表明：盐度升高使鳃Na+-K+-ATP酶活力上升，第7 d 时3个试验组Na+-K+-ATP酶活性均达到峰值且盐度8和12组显著高于淡水组（P<0.05）。肝脏SOD和CAT活性均表现为先上升后下降的趋势，且分别于胁迫12 h和2 d时达到最大值；3个盐度组的GSH-PX酶活性在6 h和12 h均有所升高，且盐度12组显著高于淡水组（P<0.05）。盐度4、8和12组肝脏MDA含量分别在第1 d和7 d达到最大值且显著高于淡水组（P<0.05）。组织切片结果显示，盐度12组的鳃小片变窄，鳃小片间距变大，泌氯细胞数量增多；肝细胞空泡化严重，血窦扩张范围增大，并出现细胞轮廓模糊、细胞核偏移、细胞核溶解。上述结果表明，盐度胁迫对大鳞副泥鳅的Na+-K+-ATP酶、抗氧化酶活性具有显著的诱导作用，并对其鳃和肝组织造成损伤。

Effects of Salinity on Antioxidant Enzymes and Histological Structure of Paramisgurnus dabryanus

To evaluate the effects of salinity on the activities of Na+-K+-ATPase and antioxidant enzymes, and histological structure of Paramisgurnus dabryanus, the P. dabryanus with the average full length of (17.60±0.69) cm and the average body mass of (35.51±5.30) g were exposed to different salinities ( fresh water, 4, 8, and 12 ) for 14 days. The results showed that the activity of Na+-K+-ATPase in gills increased with the increase of salinity, and the activity of Na+-K+-ATPase reached the peak at the 7 days, and the activities in salinity 8 and salinity 12 groups were significantly higher than those in the control group (P< 0.05).The activities of SOD and CAT increased first and then decreased, and reached the maximum at 12 h and 2 d, respectively. The activity of GSH-PX in the three salinity groups increased at 6 h and 12 h, and the activity of GSH-PX in the salinity 12 group was significantly higher than that in the control group (P < 0.05).The contentsof MDA in salinity 4, 8 and 12 groups reached the maximum at 1 d and 7 d, respectively, and were significantly higher than that of the control group (P<0.05).Histologically, the gill lamellae became narrower, the space between gill lamellae became larger, and the number of chloride- secreting cells increased. The hepatocyte vacuolization was serious, the blood sinusoid expansion scope was enlarged, and the cell outline was blurred, the nucleus was shifted, and the nucleus was dissolved.These results indicated thatthe activities of Na+-K+-ATPaseand antioxidant enzymes ofP. dabryanuswere significantly induced by salinity stress, and the histological structure of gill and liver were damaged.