TRANSPLANTABLE TUMORS ORIGINATING PROBABLY FROM THE UPPER JEJUNUM OF BUFFALO RATS

Two strains of the transplantable tumors, which originated probably from upper jejunum of male Buffalo rats fed a basal diet containing 0.025% N, N'-2, 7-fluorenylenebisacetamide for seven to nine months, are described. The original tumors had histological pictures of poorly differentiated adenocarcinoma rich in signet-ring cells and showed infiltrative growth on the peritoneal surfaces. Metastases into the lymph nodes were also found. The transplantation rates of both strains were 100% for several generations but after the 7th generation, the transplantability was reduced. In one tumor strain, successive transplantation failed at the 11th generation. The rats which received subcutaneous inoculation of another strain most recently also has not developed any palpable tumors for the last five months.