title: Effects of endogenous ovarian estrogen versus exogenous estrogen replacement on blood flow and ERβα and ERβ levels in the bladder.
abstract: OBJECTIVE
  Determine the effect of endogenous estrogen versus estrogen replacement therapy (ERT) on bladder blood flow (BBF) and estrogen receptors (ERs).
  
  
  METHODS
  BBF was determined with radiolabeled microspheres in luteal, follicular, pregnant, oophorectomized (Ovx) sheep, and Ovx sheep with ERT. Estrogen receptors (ERalpha, ERbeta) were quantified using Western blot analysis.
  
  
  RESULTS
  Compared to luteal and follicular ewes, BBF was reduced in pregnancy and following oophorectomy. Estrogen replacement therapy in Ovx sheep restored BBF to luteal levels. Estrogen receptor alpha predominated, whereas ERbeta was not detectable. Estrogen receptor-alpha levels were unaffected by the ovarian cycle and increased in pregnancy, as well as in Ovx sheep with and without chronic ERT.
  
  
  CONCLUSIONS
  The combination of diminished BBF and elevated ERalpha levels in both pregnant and Ovx sheep suggests an inverse relationship between BBF and ERalpha in the bladder. Although chronic ERT in Ovx sheep restored BBF, it did not restore ERalpha back to luteal levels.
authors.affiliation: Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Perinatal Research Laboratories, Madison, Wisconsin 53715, USA.
authors.forename: Tova S
authors.initials: TS
authors.lastname: Ablove
authors.forename: Jason L
authors.initials: JL
authors.lastname: Austin
authors.forename: Terry M
authors.initials: TM
authors.lastname: Phernetton
authors.forename: Ronald R
authors.initials: RR
authors.lastname: Magness
mesh_terms: D000818:Animals; D047628:Estrogen Receptor alpha / Q000378:metabolism / Q000502:physiology*; D047629:Estrogen Receptor beta / Q000378:metabolism / Q000502:physiology*; D015914:Estrogen Replacement Therapy / Q000379:methods; D004967:Estrogens / Q000494:pharmacology* / Q000502:physiology*; D005260:Female; D010053:Ovary / Q000187:drug effects / Q000378:metabolism*; D011247:Pregnancy; D012756:Sheep; D001743:Urinary Bladder / Q000098:blood supply* / Q000187:drug effects / Q000378:metabolism*
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens