The development of trypanosomes, leishmaniae and ascitic tumour cells in the testicles of laboratory animals

Abstract T. b. brucei, T. b. rhodesiense and T. b. gambiense multiply in the interstitial tissue when inoculated into the testicles of rabbits and guinea-pigs; T. b. gambiense grows more slowly than the other two. T. b. rhodesiense sometimes causes gangrene of the testicle and overlying skin of the rabbit. All three spread to the uninoculated testicle of rabbits and guinea-pigs after 1–3 weeks. T. cruzi developed readily in the testicle of a hamster, numerous amastigotes appear-in the Sertoli cells of the tubules. No parasites were seen in the interstitial tissue. T. vivax did not develop in the testicles of rabbits, but multiplied readily in the testicle of a kid. T. lewisi failed to multiply in the testicles of rabbits and guinea-pigs. Leishmania enriettii grew vigorously and rapidly in the testicles of hamsters, numerous amastigotes appearing in cells in the interstitial tissue, and occasionally in cells of the lamina propria. L. donovani developed similarly but more slowly. In testicles inoculated with T. b. brucei, T. b. rhodesiense, T. b. gambiense and T. cruzi spermatogenesis was interfered with. With the first three trypanosomes inoculated testicles became smaller and harder, and sections showed interstitial fibrosis, particularly in rabbits. Ascitic tumours of the Downe's type grew in columns in the interstitial tissue of the testicle of a hamster and a white rat. The tumour cells disappeared after about a fortnight.