盐度对银鲳(Pampus argenteus)Na^＋／K^＋-ATP酶活力及血清渗透压调节激素浓度的影响

THE EFFECTS OF SALINITY ON Na^+/K^+-ATPase ACTIVITY AND PLASMA OSMOREGULATORY HORMONE CONCENTRATION IN SILVER POMFRET PAMPUS ARGENTEUS

采用检测银鲳(Pampus argenteus)幼鱼鳃Na+/K+-ATP(NKA)酶活力、血清生长激素(GH)、胰岛素样生长因子Ⅰ(IGF-Ⅰ)和催乳素(PRL)浓度的方法,研究了不同盐度下银鲳渗透压调节机制。结果表明,鳃NKA酶活力在三种盐度下总体呈先上升后恢复的变化,其最高点为14盐度48h时,且显著高于其它值(P<0.05)。36盐度组的血清GH浓度显著高于其它组(P<0.05)。盐度变化均使血清IGF-Ⅰ浓度呈现先上升后恢复的变化。14盐度组血清催乳素浓度始终高于其它各盐度组。在低盐度适应(14和25)时,血清GH浓度与NKA酶活力呈极显著正相关(P<0.01);高盐度适应(36和25)时,血清催乳素浓度与NKA酶活力呈显著负相关(P<0.01)。另外,血清催乳素与IGF-Ⅰ浓度间有极显著正相关(P<0.01)。研究证明银鲳幼鱼在适应不同盐度时,鳃NKA酶、生长激素、IGF-Ⅰ和催乳素在渗透压调节中起着重要作用,并且相互之间存在一定关联。

To understand the osmoregulatory mechanism of juvenile silver pomfret Pampus argenteus, we tested the gill Na＋/K＋-ATPase （NKA） activity, plasma growth hormone, insulin-like growth factor-Ⅰ（IGF-Ⅰ）, and prolactin （PRL） concentrations in different salinities and durations. The results show that gill NKA activities increased first and then recovered in overall. At salinity 14 in 48h, the peak activity was significantly higher than other points （P〈0.05）. The plasma GH concentrations at salinity 36 were very different from other salinity （P〈0.05）. The plasma IGF-Ⅰ concentrations at both salinities 14 and 36 increased first and then recovered. The plasma PRL concentrations at salinity 14 were always higher than those of other salinity groups. Plasma GH concentration and gill NKA activity were positively correlated significantly （P〈0.01） in low salinity adaption （14 and 25）; plasma PRL concentration and gill NKA activity were negatively correlated significantly （P〈0.01） in high salinity （36 and 25）. In addition, plasma PRL and IGF-Ⅰ concentrations were positively correlated significantly （P〈0.01）. Therefore, we believed that gill NKA, plasma GH, PRL and IGF-Ⅰ were involved in osmoregulation of silver pomfret adapting for different salinity.