三疣梭子蟹在低盐胁迫下渗透生理适应性的研究

A Study on Penetration Physiological Adaptation of P.trituberculatus Under Low Salinity

本文研究了盐度胁迫对三疣梭子蟹（Portunustrituberculatus）血淋巴渗透压、鳃丝离子转运酶活力和生物胺含量的影响。结果表明：盐度胁迫（31→26、31→21）对三疣梭子蟹血淋巴渗透压、鳃丝离子转运酶活力和生物胺含量影响显著（P〈0.05）,而对照组无明显变化。各处理组蟹体渗透压在实验时间内呈峰值变化,至24h时达到最小值,72h后保持稳定,但明显低于对照组水平,且2个处理组无明显差异。各处理组蟹鳃丝Na＋-K＋-ATPase活力在0-72h内呈峰值变化,至12h达到最大值,72h后恢复至对照组水平并保持稳定;V-ATPase和HCO-3-ATPase活力在实验时间内呈上升趋势,但与对照组差异不显著（P〉0.05）。各处理组蟹鳃丝多巴胺（DA）含量在0-24h内呈峰值变化（P〈0.05）,至12h时达到最大值,24h后恢复至对照组水平并保持稳定;各处理组蟹鳃丝5-羟色胺（5-HT）含量在3-72h内呈峰值变化（P〈0.05）,至12h时达到最大值,72h后恢复至对照组水平并保持稳定;各处理组蟹鳃丝去甲肾上腺素（NE）含量在0-72h内呈峰值变化,至12h时达到最大值,72h后恢复至对照组水平并保持稳定。由此可见,三疣梭子蟹在低盐胁迫下短时间内达到渗透平衡,而鳃丝Na＋-K＋-ATPase活力变化稳定滞后,且均表现出明显的时间规律性,同时鳃丝DA和5-HT、NE含量分别与血淋巴渗透压和鳃丝Na＋-K＋-ATPase活力的变化相吻合,这说明三疣梭子蟹在低盐胁迫下生物胺短时间内发生变化,迅速调节达到渗透平衡,并激活鳃丝Na＋-K＋-ATPase活力,调节体内外离子浓度维持渗透压的稳定。

The purpose of this study was to investigate the effect of low salinity stress on hemolymph os- motic pressure, gill ion transportation enzyme activities and biogenic amine content in swimming crab （Portunus trituberculatus）. The results indicated that salinity stress had significant effect （P〈0.05） on hemolymph osmotic pressure, gill ion transportation enzyme activities and biogenic amine contents. The hemolymphosmotic pressure decreased significantly （P〈0.05） in the treatment groups and reached the lowest level at 24 h, then tended to be stable after 72 h, but was significantly lower than the control group. The Na＋-K＋-ATPase activity increased significantly （P〈0.05） in the treatment groups and reached the highest level at 12 h, then tended to be stable after 72 h, but there were no significant effect on V-ATPase and HCO3^--ATPase activities. DA content increased significantly （P〈0.05） at 3, 6 and 12 h in the treatment groups, and reached the peak at 12 h, then recovered to control level and kept constant; 5-HT content increased significantly （P〈0. 05） at 6, 12 and 24 h in the treatment groups and reached the highest at 12 h, then recovered to control level at 72 h; NE content increased significantly （P〈0.05） at 3, 6, 12 and 24 h in the treatment groups and reached the highest at 12 h, then recovered to control level after 72 h. These results suggested that Portunus trituberculatus reached the osmotic balance in a short time under low salinity, while the changes of gill Na＋-K＋-ATPase activity of stable lagged behind, and these changes had a significant time-dependent relationship. Mean-while, DA, 5-HT and NE contents were consistent with the changes of haemolymphosmotic pressure and Na＋-K＋-ATPase activity, respectively. These results indicated that biogenic amines of Portunus trituberculatus changed in a short time under low salinity, and quickly adjusted the osmotic balance, and activated the Na＋-K＋-ATPase activity, then regulated ion concentration to maintain a stable osmotic pressure.