RESUMO
Schistosoma mansoni (Puerto Rican strain) cercariae were exposed to 10, 20, 50, 100, 200, 300, 400 and 500 krad gamma radiation from 60Co gamma source. From 10-100 krad irradiation no differences could be found in the behaviour of the cercariae when compared to the controls. From 200-500 krad there was an increase in mortality as well as in the number of cercariae that shed their tails. The Con A binding studies also performed on cercariae radiated with up to 100 krad indicate a direct relationship between the number of cercariae that bind Con A and radiation dose. All live cercarial heads collected after radiation also bound Con A. It thus seems possible that irradiation may act as a stimulus for cercariae to transform to schistosomulae.
Assuntos
Raios gama , Schistosoma mansoni/efeitos da radiação , Animais , Biomphalaria/parasitologia , Concanavalina A/metabolismo , Relação Dose-Resposta à Radiação , Camundongos , Schistosoma mansoni/metabolismo , Pele/parasitologiaRESUMO
The granulocyte response of B. africanus was investigated after infection with either a compatible or a non-compatible trematode parasite. In both experiments a decrease in the granulocyte numbers was observed 7 days post-infection. This was maintained for 20 days. An observation made after 42 days showed that the numbers had recovered to normal. The granulocyte numbers of snails previously infected with S. mansoni (non-compatible) also showed a decrease 7 days after a reinfection. In this case, however, recovery of the numbers was apparent 14 days later. No sporocyst material was present in the head-foot areas of the snail 12 h post-penetration, indicating that they were already destroyed by the snails defence system.
