Plasma lactic dehydrogenase in mice infected with Japanese encephalitis & West Nile viruses.

A study of the total and isoenzymes fractions of lactic dehydrogenase (LDH) enzyme was carried out in the plasma of mice infected with Japanese encephalitis (JE) and West Nile (WN) viruses. Only 2 isoenzymes (LDH 4 and LDH 5) were present in control mice. There was a rapid increase of total LDH in the animals infected with the wild strain of viruses. Mice infected with wild strains of JE showed all 5 isoenzymes. LDH 1 disappeared after 12 days of infection but LDH 2 and LDH 3 persisted for 3 wk. The attenuated strain of JE did not produce any change either of the total content of the enzyme or of the isoenzyme pattern. In the plasma of mice infected with wild strains of WN viruses only 4 isoenzyme bands (LDH 2, 3, 4, 5) were detected. The LDH 3 persisted longer than LDH 2. With one strain of WN virus an extra band near LDH 4 was seen.