Effects of stressful conditions on the development and movement of reproductive cells in Schistosoma japonicum.

Adult S. japonicum exposed to 3H-thymidine to label reproductive cells were cultured in vitro, maintained intraperitoneally, or transplanted as unisexual infections to hamsters. Daily samples were taken, processed for autoradiography, and observed for abnormal morphological and developmental characteristics. By day 5 of in vitro culture in Medium 199 and calf serum, all worms were dead. The vitelline system was the most sensitive to culture conditions and labeled vitelline cells never moved from the gland area. No labeled sperm were produced by males and evidence of deterioration of the testes was apparent by day 2. Degenerative changes of the ovary were the last to appear, on day 3. Most adults transplanted to the peritoneal cavity of hamsters were dead by day 3, but some lived for 6 days. No movement or development of reproductive cells was detected in these worms. An intense cellular reaction directed against the tegument was observed as early as day 1. Males transplanted in groups to the hepatic portal system were maintained normally in vivo and produced labeled sperm in 6 days. Females handled similarly showed degenerative changes in their genitalia by day 2, but most were alive after 6 days.