[Spontaneous tumors in rats bred at the N.N. Petrov Research Institute of Oncology of the USSR Ministry of Health].

The paper discusses spontaneous tumor profile in albino rats bred at the N. N. Petrov Research Institute of Oncology of the USSR Ministry of Health (1981-1984). The overall incidence of tumors and that of malignant ones were shown to be 27.2 and 12.5%, respectively, in males and 47.4 and 16.4%, respectively, in females. Pituitary and hemopoietic tumors most frequently occurred in males (67%). Female rats most often revealed tumors of the pituitary, breast and hemopoietic system (90%). On the whole, the tumor profile proved identical in the animal population studied and that of Rappolovo farm of the USSR Academy of Medical Sciences. However, infection resistance in the former population was superior.