Biochemical Properties of Coho Salmon Artificially Infected with Erythrocytic Inclusion Body Syndrome Virus

Abstract

Biochemical properties of coho salmon artificially infected with the virus causing erythrocytic inclusion body syndrome (EIBS) were examined. In experimental fish injected with a homogenate from the erythrocytes of moribund fish naturally infected with EIBS, inclusion bodies were observed in erythrocytes at 2-3 weeks postinjection and hematocrit values decreased significantly at 4-5 weeks post-injection. Blood phosphatidylcholine hydroperoxide values of infected fish were lower than those of control fish. Polyunsaturated fatty acids composition of hepatic phospholipids from infected fish was lower than that of controls, and an unknown peak appeared in the fatty acid chromatogram at 4 weeks post-injection. Although gill Na⁺-K⁺ ATPase activity was not affected by EIBS infection, renal Na⁺-K⁺ ATPase activity of infected fish decreased at 4-5 weeks post-injection. These results suggested that lipid peroxidation was not caused by EIBS infection directly, but that fatty acid metabolism of fish and renal Na⁺-K⁺ ATPase activity were affected by the viral infection.