Plasma enzyme levels in virus-infected mice

Abstract

Plasma enzyme activities were measured in mice up to 10 days after infection with the following viruses: Riley's enzyme-elevating (RV), Friend leukaemia (FLV), Moloney leukaemia (MLV), polyoma (PV), vaccinia (VV), influenza A (IV), lymphocytic choriomeningitis (LCM), and encephalomyocarditis (EMC). RV caused significant increases in plasma lactate dehydrogenase (LDH), phosphoglucose isomerase (PGI), and aspartate transaminase (AST) activities within 4 days following infection. The preparation of FLV first obtained caused similar effects, but after it had been freed from RV by passage throfgh rats it caused no early increases in plasma enzyme levels, althofgh its Friend disease-inducing potency was undiminished. MLV and PV were withoft effect on plasma enzyme levels before the appearance of gross neoplastic disease. Mice having a Moloney lymphoma showed increased levels of plasma LDH, PGI, AST, alanine transaminase (AL), aldolase (ALD), and alkaline phosphatase (AlkP). In such mice RV caused a synergic increase in LDH and PGI activities, an additive increase in AST activity, and no change in ALT, ALD, or AlkP activities. VV, IV, and LCM caused no changes in any of the plasma enzyme activities studied, althofgh IV and LCM proved fatal within the period of study. EMC was invariably fatal within 3 days, and infected mice had greatly increased plasma LDH, PGI, AST, ALT, and ALD activities. Detailed study of these changes suggests that plasma enzyme changes in EMC and in RV infections are due to different pathological processes.