Study On Crustacean Hyperglycemia Hormone (CHH) Modulates The Osmoregulation And Glucose Metabolism Of Litopenaeus Vannamei

There are lots of researchers focusing on the osmoregulation of Crustacean, which is a very important physiological function maintaining normal vital movement. But there were few correlative studies has reported, especially on the change of pathway factors of Crustacean osmoregulation modulated by the Neuroendocrine system. Litopenaeus vannamei is one of the three shrimps which have the largest production in the world, and have the largest production in China. It has many advantages, including fast growth rate, adaptability to high density and broad salinity and low demand to protein. The report studies the changes of osmoregulation factors modulated by CHH, the effect of Neuroendocrine hormone on the osmoregulation of Litopenaeus vannamei and the mechanism of the osmoregulation according to the changes of relating factors.1 Cloning and sequence analysis of CHH in Litopenaeus vannameiCHH is very important in the growth and reproduction of Crustacean. The degenerate primers were designed from CHH protein multiple sequence alignments from related species. The partial CHH cDNA sequence was obtained through the technology of RT-PCR. The results show that CHH is highly conserved when compared among species, especially the CHH cDNA of shrimps, Together on a branch in the evolutionary tree. And it can be drawn from the experiment that CHH mRNA expresses in abdominal nerve, eyestalk, heart,hepatopancreas and muscle. It is lowly expressed in muscle and isn't expressed in gill.2 Effect of Eyestalk Ablation on the pathway of signal transport ion of gill of Litopenaeus vannameiThe studies shows that the changes of contents of three kinds of biogenic amines, cAMP and cGMP and three kinds of ion transportation enzyme activity in gills. The results show that eyestalk ablation can affect significantly contents of three kinds of biogenic amines and cGMP and three kinds of ion transportation enzyme activities in gills (p<0.05), and can not affect significantly contents of cAMP (p>0.05). The contents of three kinds of biogenic amines, cAMP and cGMP and three kinds of ion transportation enzyme activities in the gills of control group and hunger group don't change significantly (p>0.05). The concentration of DA and NE in the gill of eyestalk ablation group and interactive group showed peak changes within 48h, reached the peak value at 12h, then decreased and were finally lower than the control group at 48h (P<0.05). The contents of 5-HT in the gill of excising eyestalk group showed peak changes within 48h, reached the minimum value at 12h, then increased slowly, became stable and was finally lower than the control group at 48h (P<0.05). But the contents of 5-HT in the gill of interactive group decreased significantly and was finally lower than the control group at 48h (P<0.05). The concentration of cAMP in the gill of eyestalk ablation group decreased at first and then increased. The contents of cAMP in the gill of interactive group decreased slowly and had no significant differences from the control group at 48h. The concentration of cGMP in the gill of eyestalk ablation group and interactive group had negative correlation with treat time, decreased and was finally lower than the control group at 48h (P<0.05). Na⁺-K⁺-ATPase and HCO₃^--ATPase activity in the gill of eyestalk ablation group showed peak changes within 48h, reached the minimum value at 12h, and then increased. Na⁺-K⁺-ATPase recovered to control level. But HCO₃^--ATPase activity was finally lower than the control group at 48h (P<0.05). Na⁺-K⁺-ATPase and HCO₃^--ATPase activity in the gill of interactive group decreased significantly and was finally lower than the control group at 48h (P<0.05). V-ATPase activity in the gill of excising eyestalk group and interactive group decreased significantly, became stable at 24h and was finally lower than the control group (P<0.05). The concentration of three kinds of biogenic amines, cAMP and cGMP, Na⁺-K⁺-ATPase, V-ATPase and HCO₃--ATPase activity in the gill of eyestalk ablation group were higher than those of interactive group. Eyestalk removal affected significantly biogenic amines, second messengers and ion transportation enzyme activity. And the data of eyestalk ablation group was higher than that of interactive group. The result indicated that huger induced the changes of signal channel and activated the target organ to regulate osmotic equilibrium according to biogenic amines and second messengers.3 Effect of eyestalk ablation on the hemolymph glucose metabolism of Litopenaeus vannameiThe report studies the effects of eyestalk ablation on the contents of three kinds of biogenic amines in hemolymph, cAMP, cGMP in the hepatopancreas and the hemolymph glucose. The result indicated that eyestalk removal affected significantly the contents of three kinds of biogenic amines in hemolymph, cAMP, cGMP in the hepatopancreas and the hemolymph glucose (P<0.05). But there were no significant differences in those of control group(p>0.05). The contents of DA and NE in the hemolymph of huger group showed peak changes within 48h, reached the peak value at 12h. The content of 5-HT in huger group increased and then decreased, but didn't change significantly. The contents of three kinds of biogenic amines was finally lower than the control group at 48h (P<0.05). The concentration of DA in the hemolymph of eyestalk ablation group decreased and was finally lower than the control group at 48h (P<0.05). The content of NE in the hemolymph of eyestalk ablation group showed peak changes within 48h, reached the minimum value at 12h and was finally higher than the control group at 48h (P<0.05). The content of 5-HT in the hemolymph of eyestalk ablation group didn't change significantly, and had no significant difference with the control group at 48h (p>0.05). The content of DA and NE in the hemolymph of interactive group decreased during the experiment and was finally lower than the control group at 48h (P<0.05). The content of 5-HT in the hemolymph of interactive group increased, then decreased and recovered to control level. The content of cAMP in the eyestalk ablation group showed peak changes within 48h, reached the minimum value at 12h, then increased and recovered to control level at 48h. The content of cGMP in the eyestalk ablation group decreased, reached the minimum value at 24h, then became stable, and was finally lower than the control group at 48h (P<0.05). The contents of cAMP and cGMP in the interactive group showed peak changes during the experiment, reached the minimum value at 12h, and then increased. The content of cAMP became stable at 24h and was finally lower than the control group at 48h (P<0.05). But the content of cGMP recovered to control level at 48h. The content of hemolymph glucose in huger group decreased during the experiment and had significant difference with the control level (P<0.05). The content of hemolymph glucose in eyestalk ablation group showed peak changes during the experiment, reached the minimum value at 24h, then increased and was finally higher than the control group at 48h (P<0.05). The content of hemolymph glucose in the interactive group decreased to about 0 during the experiment and was finally lower than the control group at 48h (P<0.05). The results indicated that eyestalk ablation affected significantly the hemolymph glucose metabolism of Litopenaeus vannamei. The contents of biogenic amines in hemolymph and the hemolymph glucose in no eyestalk ablation groups was lower than the control level. The contents of cAMP and cGMP was higher than the control level. The data of eyestalk ablation group were all higher than interactive group. The results indicated that huger activated second massagers in the cell and then regulated target organ related to hemolymph glucose. Litopenaeus vannamei can maintain physiological equilibrium according to obtain energy from food in the absent of CHH.