Induction of Leukemia in Rats with Mouse Leukemia (Passage A) Virus.

Abstract

A mouse leukemia virus, originally isolated from spontaneous Ak leukemia, then passed serially through newborn mice (passage A), and consistently leukemo-genic for suckling mice of susceptible strains, was found to be leukemo-genic for newborn rats. Following intraperitoneal inoculation of passage A filtrates into newborn Sprague-Dawley rats, leukemia developed in from 48% to 73% of the inoculated animals, after a latency varying from 2 1/2 to 4 1/2 months. Either localized thymic lymphosarcomas, or generalized lymphatic leukemia, involving also spleen, liver, and mesen-teric lymph nodes, developed in the inoculated animals. A few rats developed acute stem cell leukemia.