DEVELOPMENT OF RAT AND HAMSTER STRAINS OF NIPPOSTRONGYLUS BRASILIENSIS IN GONADECTOMIZED MALE RATS AND HAMSTERS

The development of homologous (rat-rat strain; hamster-hamster strain) and heterologous (hamster-rat strain; rat-hamster strain) strains of N. brasiliensis was compared in gonadectomized male rats and hamsters to test the hypothesis that development of the parasite was dependent to some extent upon the degree of adaptation between host and parasite. The intensity of infections in gonadectomized animals was significantly less than that of the controls in the heterologous but not in the homologous host parasite systems. The present findings support those that suggest that serial passage of the parasite in the hamster results in a change in the parasite population rendering it less fit in its original host environment. © 1968.