Abstract
Roller tube tissue cultures of rhesus kidney cortex were assayed, inoculated with various strains of polio viruses and paralleled by normal controls of the same lot. Supernatant fluids or whole homogenates were tested for the activity of phosphatases, nucleo-tidases, nucleases and pseudo-cholinesterase. Marked decrease in activity of these enzyme systems was seen at the height of virus infection, in vitro. These changes are the expression of radical changes in cell physiology and are preceding the visible cytopathogenic effect (CPE). The inhibition of essential enzyme systems may explain the mode of action of the virus, may be the cause, and may serve as a quantitative measure of the CPE. The simultaneous changes in the tissue mass and in nutrient medium are demonstrated by turbidimetric and spectrophotometric analysis. Various other aspects of the subject and the theoretical and practical bearing of the findings are discussed.