Renal cell tumors induced in CBA male mice by 1,2-dimethylhydrazine.

Epithelial kidney tumors induced in CBA male mice by 1,2-dimethylhydrazine (DMH) were studied histochemically and immunohistochemically. A total of 48 tumors studied histologically were diagnosed as clear-cell, acidophilic, or mixed adenomas located in the renal cortex. Gamma-glutamyl transpeptidase (GGT) was strongly positive in normal proximal convoluted tubules, slightly positive in the cells of Bowman's capsule, and negative in 47 of 48 tumors examined. Antibodies against the new antigen 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 positive in all 47 GGT-negative tumors studied here. One tumor was GGT-positive and antigen A6-negative. Based on our data, it was concluded that the majority of renal cell adenomas induced by DMH in mice probably originate from the distal tubules or collecting ducts and not from the proximal tubules.