title: Inhibition by tocopherol of prostaglandin-induced apoptosis in ovine corpora lutea.
abstract: Accumulation of toxic oxidants within corpora lutea is a prelude of apoptotic cell death. Vitamin E (alpha-tocopherol) is a biological antioxidant that protects cells from the inductive effects of reactive oxygen on DNA damage and nuclear/cytoplasmic condensation that dictate apoptosis. Ewes were challenged with a luteolytic dose of PGF2 alpha on d 10 of the estrous cycle. The acute decline in circulatory progesterone indicative of the onset of functional luteolysis was not affected by systemic administration of alpha-tocopherol; however, corpora lutea consequently (beyond 24 h) rebounded from the steroidogenic insult. Luteal tissues obtained at 24 h after PGF2 alpha revealed that internucleosomal DNA fragmentation and cellular collapse were inhibited by alpha-tocopherol. These observations indicate that regressive corpora lutea can be spared from terminal involution by diminishing the apoptotic influence of luteolytic hormone with an antioxidant.
authors.affiliation: Department of Animal Science, University of Wyoming, Laramie 82071, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Vierk
authors.forename: T R
authors.initials: TR
authors.lastname: Hansen
authors.forename: K J
authors.initials: KJ
authors.lastname: Austin
authors.forename: E A
authors.initials: EA
authors.lastname: Van Kirk
authors.forename: B W
authors.initials: BW
authors.lastname: Hess
authors.forename: W J
authors.initials: WJ
authors.lastname: Murdoch
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001345:Autoradiography; D003338:Corpus Luteum / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D004247:DNA / Q000032:analysis; D015237:Dinoprost / Q000037:antagonists & inhibitors; D005260:Female; D010053:Ovary / Q000502:physiology; D011374:Progesterone / Q000032:analysis / Q000097:blood; D011448:Prostaglandin Antagonists / Q000502:physiology*; D012756:Sheep / Q000502:physiology; D013997:Time Factors; D014018:Tissue Distribution; D014810:Vitamin E / Q000494:pharmacology*