Total carbohydrate and glucose concentrations increase in WSSV-infected shrimp . We found that total carbohydrate
selleck chemicals concentrations in the hemolymph of the shrimp F. indicus had significantly increased 72 hrs after transferring them into 5 and 35 g/L salinity. In shrimp, hemolymph glucose and total carbohydrate concentrations are known to increase under stressful conditions. Hall and Van Ham reported significant increases in hemolymph glucose concentrations in the shrimp P. monodon under stress conditions . The present study showed that total lipid concentrations increased significantly after 120 hrs in shrimp that had been subjected to salinity stress. Because shrimp cannot synthesize cholesterol de novo , the high cholesterol concentrations seen at all salinities were considered a clear indication that stress had affected lipid transport. Significant reduction of hemolymph metabolites in infected shrimp under salinity stress may be attributable to deviation of energy flow toward supporting osmotic adjustment because they are under dual stress (both salinity and infection-related stress). Metabolic variables correlate with some or all of the immune variables studied; it is therefore clear that poor metabolism may lead to a
decrease in immunocompetence. Decrease in fatty acid concentrations in hemolymph RO4929097 in vitro of infected shrimp is a recognized phenomenon ; the reason for this is yet to be defined. We found hyperglycemia with WSSV infection only in shrimp maintained at 15 g/L and not in those in the other salinities tested. Increased secretion of crustacean hyperglycemic hormone may cause hyperglycemia. In the present study, Aldol condensation significantly lower THC was observed in 15–35 g/L at 120 hrs after injection of WSSV. The decreased THC found in WSSV-infected shrimps at all salinities is most likely caused by accumulation of hemocytes at the site of injection for wound healing and phagocytosis . We found a correlation between
significantly increased PO activity and THC at 25 g/L after injection with WSSV. A low circulating hemocyte count correlates strongly with greater sensitivity to pathogens . Thus the reduction in THC that occurs after salinity stress due to cell lysis, diapedesis or osmosis of water between hemolymph and the medium may therefore be interpreted as a major factor in decreasing immunocompetence . After challenge with WSSV, SOD, ALP and ACP activities significantly increased under salinity stress in F. indicus. The activity of ALP and ACP, which play a key role in destroying extracellular invaders , could be related to the phagocytic ability of hemocytes. Salinity variations reportedly lower resistance to Photobacterium damselae subsp. damselae in P. monodon . In conclusion, the present study indicates that acute variations in salinity alter metabolic variables in hemolymph of F.