title: Histopathological effects induced by paraquat during Xenopus laevis primary myogenesis.
abstract: The oxidative agent paraquat induced tail abnormalities during Xenopus laevis development. Specimens exposed from blastula to the tadpole stage revealed pear-shaped myocytes and irregular intersomitic boundaries. The histological feature of the axial musculature was evaluated in embryos sampled at significant stages of the primary myogenesis. During the somitogenesis PQ-treated embryos showed normal appearing myotomes, but reduced PAS activity in the post-rotating myotomal cells, and myoblasts with slight vacuolations. Once etched from the vitelline envelope, embryos showed severely altered myoblasts with irregular cellular apexes, heavy sarcoplasmic vacuolations, pyknotic nuclei and disorganizing intersomitic boundaries. Myotomes with many necrotic myocytes containing disorganized contractile material and heavily malformed intersomitic boundaries characterized the late myogenic stages. Our results evidence the heaviest PQ histopathological effects to affect myogenesis of post-etched embryos, suggesting a possible linkage between the swimming activity and the oxidative damage to muscle tissue.
authors.affiliation: Dipartimento di Scienze dell'Ambiente e del Territorio, Università degli Studi di Milano-Bicocca, 1, Piazza della Scienza, I-20126 Milan, Italy. paride.mantecca@unimib.it
authors.forename: P
authors.initials: P
authors.lastname: Mantecca
authors.forename: S
authors.initials: S
authors.lastname: Panseri
authors.forename: R
authors.initials: R
authors.lastname: Bacchetta
authors.forename: C
authors.initials: C
authors.lastname: Vismara
authors.forename: G
authors.initials: G
authors.lastname: Vailati
authors.forename: M
authors.initials: M
authors.lastname: Camatini
mesh_terms: D000818:Animals; D036703:Blastula / Q000378:metabolism* / Q000648:ultrastructure; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000648:ultrastructure; D006540:Herbicides / Q000494:pharmacology / Q000633:toxicity*; D024510:Muscle Development / Q000187:drug effects*; D018485:Muscle Fibers, Skeletal / Q000378:metabolism* / Q000648:ultrastructure; D009336:Necrosis / Q000139:chemically induced / Q000473:pathology; D010269:Paraquat / Q000494:pharmacology / Q000633:toxicity*; D019170:Somites / Q000378:metabolism / Q000648:ultrastructure; D014982:Xenopus laevis
chemical_list: D006540:Herbicides; D010269:Paraquat