title: Morphological changes in the reproductive organs of male and female Schistosoma mansoni worms caused by streptozotocin, a drug used to induce diabetes mellitus.
abstract: Host metabolic changes have been observed to affect Schistosoma mansoni egg production, worm survival and morphology. We examined worms recovered from streptozotocin-induced diabetic mice by morphometric and morphological analysis through brightfield and confocal laser scanning microscopy. Tegument thickness was slightly smaller and changes in the reproductive organs were observed in 23-30% and consecutively 88-100% of the worms. The testicular lobes had a large diminution of cells in one or more of the lobes, which was associated with a lack of spermatozoids in the seminal vesicle. Ovaries were atrophied, manifested by a complete or large reduction in oocytes but other parts of the reproductive system like the vitelline glands were mainly unaffected. Streptozotocin (STZ) instead of hyperglycaemia caused the degeneration since worms from mice injected with a non-diabetogenic dose, or with nicotinamide to prevent diabetes showed the same alterations. The drug did not affect worm survival or pairing. We conclude that STZ, an alkylating agent that provokes chromosome and DNA damage, changes the morphology of ovaries and testicular lobes in S. mansoni worms in vivo. This is the first report of STZ action in helminths and we suggest that STZ affects oogenesis and spermatogenesis and might cause sterilization of schistosomes.
authors.affiliation: Biologia Parasitária, Departamento de Ensino, Pavilhão Arthur Neiva, Instituto Oswaldo Cruz, Fiocruz, Avenida Brasil 4365, Manguinhos, 21045-900, Rio de Janeiro, RJ, Brasil.
authors.forename: M
authors.initials: M
authors.lastname: Hulstijn
authors.forename: L A
authors.initials: LA
authors.lastname: Barros
authors.forename: R H
authors.initials: RH
authors.lastname: Neves
authors.forename: E G
authors.initials: EG
authors.lastname: Moura
authors.forename: J R
authors.initials: JR
authors.lastname: Machado-Silva
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced; D005260:Female; D008297:Male; D051379:Mice; D010053:Ovary / Q000187:drug effects* / Q000473:pathology; D010063:Ovum / Q000187:drug effects / Q000473:pathology; D012550:Schistosoma mansoni / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology; D012556:Schistosomicides / Q000494:pharmacology; D013311:Streptozocin / Q000494:pharmacology*; D013737:Testis / Q000187:drug effects* / Q000473:pathology
chemical_list: D000900:Anti-Bacterial Agents; D001786:Blood Glucose; D012556:Schistosomicides; D013311:Streptozocin