title: Enhancement of aromatase gene expression in the mediobasal hypothalamus during anestrus in the beagle bitch.
abstract: The relationships among expression of cytochrome p450 aromatase (p450arom) mRNA in the mediobasal hypothalamus (MBH), ovarian aromatase activity, and estrogen secretion were examined throughout the estrous cycle in beagle bitches. Using polymerase chain reaction (PCR) analysis we were able to detect p450arom gene transcripts in the canine MBH. The level of hypothalamic p450arom mRNA increased during the progression of anestrus and declined thereafter. Ovarian p450arom activity, as measured by a (3)H2O assay, were low in anestrus, increased in proestrus, and declined thereafter. Ovarian p450arom activity and plasma estradiol-17beta levels were positively correlated (r=0.77, P<0.05). These results suggest that enhancement of hypothalamic p450arom gene expression is associated with termination of anestrus.
authors.affiliation: Laboratory of Cell Pathobiology, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Osaka 599-8531, Japan. inaba@vet.osakafu-u.ac.jp
authors.forename: Toshio
authors.initials: T
authors.lastname: Inaba
authors.forename: Tamaki
authors.initials: T
authors.lastname: Namura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tani
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsuyama
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Torii
authors.forename: Noritoshi
authors.initials: N
authors.lastname: Kawate
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Tamada
authors.forename: Shingo
authors.initials: S
authors.lastname: Hatoya
authors.forename: Daijiro
authors.initials: D
authors.lastname: Kumagai
authors.forename: Kikuya
authors.initials: K
authors.lastname: Sugiura
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sawada
mesh_terms: D000780:Anestrus / Q000235:genetics*; D000818:Animals; D001141:Aromatase / Q000235:genetics*; D004285:Dogs; D004958:Estradiol / Q000097:blood; D005260:Female; D015870:Gene Expression; D007033:Hypothalamus, Middle / Q000502:physiology*; D010053:Ovary / Q000201:enzymology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics*; D012194:RNA-Directed DNA Polymerase; D017423:Sequence Analysis, RNA
chemical_list: D012333:RNA, Messenger; D004958:Estradiol; D001141:Aromatase; D012194:RNA-Directed DNA Polymerase