title: Steroid hormones do not reactivate Neospora caninum in ovariectomized mice.
abstract: The direct effects of three steroid hormones (progesterone, estradiol-17beta and corticosterone) on the growth of Neospora caninum (N. caninum) tachyzoite were examined in Vero cells. Subsequently, ovariectomized BALB/c mice infected with N. caninum were treated with physiological concentrations of the steroid hormones for 1 or 2 weeks. These hormones had no direct effect on the parasite growth in vitro. In the infected mice, there was no significant difference in the parasite distribution and histopathological changes between the hormone-injected and control groups. No mice showed parasitemia at the time of autopsy. These results suggest that physiological levels of steroid hormones (progesterone, estradiol-17beta and corticosterone) do not reactivate N. caninum in mice.
authors.affiliation: Laboratory of Comparative Pathology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapparo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Seiji
authors.initials: S
authors.lastname: Katagiri
authors.forename: Takashi
authors.initials: T
authors.lastname: Kimura
authors.forename: Kenji
authors.initials: K
authors.lastname: Ochiai
authors.forename: Takashi
authors.initials: T
authors.lastname: Umemura
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology; D002522:Chlorocebus aethiops; D003048:Coccidiosis / Q000276:immunology / Q000469:parasitology* / Q000473:pathology; D003345:Corticosterone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D018688:Neospora / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development* / Q000276:immunology; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology*; D012008:Recurrence; D014709:Vero Cells
chemical_list: D000913:Antibodies, Protozoan; D011374:Progesterone; D004958:Estradiol; D003345:Corticosterone