SARCOMAS IN HAMSTERS AFTER INJECTION WITH ROUS CHICKEN TUMOR MATERIAL

Abstract

Newborn hamsters were injected subcutaneously with a suspension of finely minced Rous chicken sarcoma (Schmidt-Ruppin strain). After an interval of about 2 weeks, progressively growing sarcomas developed at the site of injection in almost all animals. Also in adult hamsters inoculated intramuscularly with the same material sarcomas developed at the site of injection within 2 to 4 months. Secondary growths appeared on the peritoneal surface, in the retroperitoneal and mediastinal lymph nodes and in the lungs. The sarcomas usually had a pleomorphic appearance and showed a certain resemblance to rhabdomyosarcoma, but sometimes they had the character of spindle cell sarcomas of varying degree of maturity. Sarcomas were not only obtained in hamsters injected with cellular material from the Rous chicken sarcoma but were also seen in hamsters which were injected at birth or when 2 months' old with supernatant fluid obtained by repeated centrifugation of suspensions of homogenized chicken sarcoma, and presumed to be cell-free.