Schistosoma mansoni: Astiban-induced damage to tegument and the male reproductive system

Astiban produced structural damage in male Schistosoma mansoni (Puerto Rican strain) in mice. The degree of disorganization was directly related to the dosage administered, although initial changes in structure for the first three doses (3 × 30–40 mg/kg) varied between individual worms of the same infection. More consistent damage to the tegument, parenchyma, and reproductive organs occurred after 6 × 40 mg/kg of Astiban injections. Exposure of the subtegumentary musculature preceded appearance of an increased number of noncytoplasmic spaces in various tissues, probably a result of osmotic stress. Testicular disorganization was prominent initially in spermatozoa and spermatids, but became more generalized with drug accumulation. The sustentacular cells showed increased phagocytic activity with testicular damage. Continuous administration of drug resulted in a general distortion of the worm's morphology. However, partial recovery occurred within 22 days following cessation of drug administration.