盐度驯化对鲤血清生化指标及渗透压的影响

Effects of salinity domestication on serum biochemistry and osmotic pressure of carp Cyp- rinus carpio.

选用7月龄的鲤(Cyprinus carpio)作为研究对象,进行了急性和慢性盐度驯化实验。探讨了鲤的半致死盐度值和在淡水及盐度为3、6、9、12、14、16下的血清生化指标和渗透压的变化。结果表明:鲤的96 h的半致死盐度值为14.33 g·L-1;各个盐度驯化组鲤的乳酸脱氢酶表现为先升高后降低又升高再降低;丙氨酸氨基转移酶、天门冬氨酸氨基转移酶、总蛋白和白蛋白均在盐度3时出现峰值,显著高于淡水组(P<0.05),随后呈现下降趋势;各个盐度驯化组鲤血糖水平呈先下降后上升趋势,但都低于淡水组水平(P<0.05);尿素含量变化比较复杂,盐度为3时出现显著上升(P<0.05),盐度为6、9时与淡水组无显著性差异(P>0.05),随后再次呈现显著上升趋势(P<0.05);随着盐度上升,鲤的血清渗透压也呈现上升趋势且均高于淡水组(P<0.05);在盐度驯化过程中鲤渗透压随着外界环境渗透压的升高而升高,同时鲤因为盐度变化而减少进食导致血糖下降,各个生化指标的变化说明鲤驯化初期对盐度的变化是敏感的,血清中尿素含量波动是由盐度变化引起鲤肾脏机能改变所致。

Taking 7-month old carps as the objects, an acute and chronic salinity domestication experiment was conducted to study the carp 96 h semi-lethal salinity value and the changes of carp serum biochemistry and osmotic pressure in freshwater and at different salinities （3, 6, 9, 12, 14, and 16）. The carp 96 h semi-lethal salinity value was 14.33 g ~ L-1. In each salinity domestication group, the carp lactate dehydrogenase activity decreased after initial increase, and increased after an initial decreased again. The alanine aminotransferase and aspartate aminotrans- ferase activities and the total protein and albumin contents were peaked at salinity 3, being signif- icantly higher than those in freshwater （ P〈0.05 ）, and then, followed by a downward trend. The blood content in each domestication group had a trend of increased after an initial decrease, but was significantly lower than that in freshwater group （P〈0.05）. The changes of urea content were more complicated, being significantly increased at salinity 3 （P 〈 0.05 ） , no significant difference in freshwater and at salinities 6 and 9 （P〉0.05） , and significantly increased with in- creasing salinity （P〈0.05）. With the increase of salinity, the serum osmotic pressure also pres- ented an increasing trend, and was higher than that in freshwater （P〈0.05）. During the salinity domestication process, the carp osmotic pressure increased with the increase of environmental os- motic pressure. At the same time, due to the salinity change, the carp eat less, leading to the decrease of blood sugar content. The changes of each biochemical indicator showed that the carp was sensitive to the salinity change at the early stage of domestication. The fluctuation of serum urea content was caused by the functional change of the carp kidney induced by the salinity change.