title: Induction of persistent estrus by constant light: effects of neonatal constant light and Harderian gland function.
abstract: The effect of constant light on the age at onset of persistent estrus was compared in rats exposed to constant light since birth (LL-0) and those exposed beginning at 70 days of age (LL-70). Persistent estrus occurred about 27 days later in the LL-0 rats than in the LL-70 rats. Exposure to LL for just the 1st 15 days of life (LL-0-15) and then subsequent exposure to LL at 71 days also delayed the induction of persistent estrus. Neonatal injection of a Harderian gland (HG) homogenate to LL-0-15 rats reduced the age of vaginal opening and 1st estrus and reduced the delayed onset of persistent estrus caused by the neonatal LL. Harderianectomy of LL-0 or hematoporphyrin injections in LL-0-15 rats had no effect on the onset of LL-induced persistent estrus.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D004971:Estrus; D005260:Female; D006243:Harderian Gland / Q000502:physiology*; D007765:Lacrimal Apparatus / Q000502:physiology*; D008027:Light; D008029:Lighting; D010053:Ovary / Q000502:physiology; D011247:Pregnancy; D051381:Rats; D012741:Sexual Maturation; D014621:Vagina / Q000502:physiology