Schistosoma mansoni: Radioautography of colchicine's effect on [3H]proline incorporation into adults in vitro

Adult Schistosoma mansoni were studied radioautographically in order to ascertain the effect of exposures to a fixed concentration of colchicine (5 × 10^?4M) for varying time intervals upon the incorporation of [³H]proline in the tegument. Additionally, a study was made on the effect of varying time exposures of colchicine on the cytochemical localization of alkaline phosphatase (EC 3.1.3.1) in the tegumental invaginations. Worms exposed to colchicine for more than 2 hr preceding addition of the labeled amino acid displayed significant changes in the pattern of distribution. The most profound change was noted in the male tegument where a statistically significant decrease was observed in treated worms. Female worms, on the other hand, failed to display any effect of the drug on the distribution pattern for the times utilized. The distribution of alkaline phosphatase activity was much reduced in the teguments of both sexes. Morphological effects of the drug included disappearance of microtubules from the cytoplasmic connectives, a stacking of RER in the subtegumental cells, and accumulation of discoid granules and membranous bodies in the subtegumental cells. It is hypothesized that the amino acid is associated with the discoid granule at the subtegumental cell level and is ultimately translocated, with the aid of microtubules in the cytoplasmic connectives, to the tegument. Alkaline phosphatase activity is assumed to be associated with the membranous body.