RENAL-CELL TUMORS INDUCED IN CBA MALE-MICE BY 1,2-DIMETHYLHYDRAZINE

Epithelial kidney tumors induced in CBA male mice by 1,2-dimethylhydra zine (DMH) were studied histochemically and immunohistochemically. A t otal of 48 tumors studied histologically were diagnosed as clear-cell, acidophilic, or mixed adenomas located in the renal cortex. Gamma-glu tamyl transpeptidase (GGT) was strongly positive in normal proximal co nvoluted tubules, slightly positive in the cells of Bowman's capsule, and negative in 47 of 48 tumors examined. Antibodies against the new a ntigen obtained from the mouse liver oval cells, antigen A6, were also used. This antigen is negative in normal kidney proximal tubules but always positive in distal tubules and collecting ducts. It was also po sitive in all 47 GGT-negative tumors studied here. One tumor was GGT-p ositive and antigen A6-negative. Based on our data, it was concluded t hat the majority of renal cell adenomas induced by DMH in mice probabl y originate from the distal tubules or collecting ducts and not from t he proximal tubules.