Studies on the properties of factors elevating the activity of mouse-plasma lactate dehydrogenase

Abstract

A transmissible agent causing a 6-10-fold in- crease in plasma lactate-dehydrogenase activity in infected mice was described by This agent was present in a number of transplantable mouse tumours, and could be transmitted by the inoculation of small quantities of plasma or tissue from tumour-bearing mice into normal mice. Such infected mice could be used successively as sources of the agent, which appeared therefore to be a transmissible virus. This work has been confirmed and extended by several groups of investigators. It was shown, for example, that the virus was not present in spon- taneous tumours from uninfected mice, that it was distinct from leukaemia virus, and that trans- plantable tumours containing the virus could be 'cured' by tissue-culture passage. From this and other evidence the agent appeared to be a ' carrier' virus picked up by mouse tumours during long periods of transplantation (Mundy & Williams, 1961;