ANALYSIS OF PROLIFERATIVE ACTIVITY IN RENAL LESIONS INDUCED BY N-NITROSOBIS(2-OXOPROPYL)AMINE (BOP) IN MALE SYRIAN GOLDEN-HAMSTERS

Binding of a specific antibody to proliferating cell nuclear antigen ( PCNA) and staining of argyrophilic proteins associated with nucleolar organizer regions (AgNORs) were investigated in proliferative lesions induced by N-nitrosobis(2-oxopropyl)amine (BOP) in the hamster kidney. Thirty male Syrian golden hamsters were given three weekly s.c. injec tions of BOP (10 mg/kg body wt.) and sacrificed for characterization o f proliferative changes 30 weeks after the first BOP treatment. Morpho logically, lesions of the tubular epithelia were classified either as tubular adenoma or dysplasia, the latter being further classified into small cluster, acidophilic cell, clear cell and cystic types. Immunoh istochemistry for PCNA revealed significant increases of cell prolifer ation activity in adenomas and acidophilic cell types of dysplasia, al ong with significantly elevated mean numbers of AgNORs per nucleus. Th e results thus indicate that the acidophilic cell type of dysplasia ma y be of prime significance as the preneoplastic renal lesion induced b y BOP.