盐度变化对黑鲷生长激素及其受体的影响

IMPACTS OF SALINITY ON GROWTH HORMONE AND ITS RECEPTOR OF BLACK SEABREAM SPARUS MACROCEPHALUS

将海水鱼类黑鲷Sparusmacrocephalus从盐度为26.6的海水直接转入淡水,考察渗透压的急剧降低对黑鲷的生长激素(growthhormone,GH)及其受体(growthhormonereceptor,GHR)等生理指标的影响。研究发现:(1)黑鲷从海水直接转入淡水后48h有33%的鱼死亡,对照组无死亡现象;(2)黑鲷在转入淡水48h内其血清生长激素(GH)含量、肝脏及鳃中GHR及GHRmRNA含量与对照组均无显著差异;(3)黑鲷在转入淡水48h后其肾脏中GHR含量较对照组显著升高(p<0.05),肾脏中GHRmRNA含量在24h及48h显著高于对照组(p<0.05)。结果表明,从GH含量看,黑鲷从海水环境到淡水低渗环境与鲑鳟鱼类从淡水到海水环境的适应性调节机制有差异,而黑鲷肾脏中GHR的含量变化可能参与黑鲷对外界环境渗透压的这种急剧降低的适应性调节。

Black seabream (Sparus macrocephalusBZ) were transferred from seawater (salinity 26.6) to freshwater to investigate the physiological response of black seabream, such as growth hormone (GH) and its receptor (GHR). Up to 33% of black seabream were dead 48 hours later after the transfer from seawater to freshwater, while no fish was found dead in the control group. Levels of serum GH, liver GHR and GHR mRNA had no significant changes in black seabream maintained in freshwater within 48 hours. Kidney GHR level in black seabream increased significantly 48 hours later after the transfer from seawater to freshwater (p<0.05), and GHR mRNA in kidney increased significantly 24 hours later after the transfer to freshwater (p<0.05). This study indicated that black seabream does not accord with salmonids in GH level when transferred from freshwater to seawater with increase of serum GH, and the change of GH receptor in kidney can regulate the hypoosmotic adaptation in black seabream.