title: Comparison of the effects of oestrogen deficiency and old age on primary bladder afferent activity and voiding behaviour in the ageing female rat.
abstract: OBJECTIVE
  To determine if a decrease in oestrogen (E) levels increases activity in bladder afferent nerves, by investigating the effects of E loss on afferent nerve activity in ovariectomized (OVX) rats, and making comparisons with findings in ageing female rats.
  
  
  METHODS
  Female Sprague-Dawley rats were divided into four groups: ageing; OVX+ E; OVX+ vehicle (V); and sham-operated (SHAM) + V. The E (250 µg/kg) or V (cottonseed oil) was injected s.c. once a week for 8 weeks. Frequency-volume recordings were performed with the rats in metabolic cages, and single Aδ- or C-fibre activities from the bladder were measured. After measurements, the blood serum was collected and the estradiol (E2) level was measured.
  
  
  RESULTS
  The C-fibre activity of OVX + V rats was significantly lower than in the other groups. Aδ-fibre activity was unchanged. Despite low E2 levels, ageing rats showed high afferent activity and voiding frequency.
  
  
  CONCLUSIONS
  Although a low E level may affect storage function, it is unlikely that it is the main cause of the high afferent activity and voiding frequency observed in the ageing female rat.
authors.affiliation: Department of Urology, Faculty of Medicine, University of Antwerp, Antwerp, Belgium.
authors.forename: Naoki
authors.initials: N
authors.lastname: Aizawa
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Iijima
authors.forename: Jan S
authors.initials: JS
authors.lastname: Rosenbaum
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Downs
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Igawa
authors.forename: Karl-Erik
authors.initials: KE
authors.lastname: Andersson
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Wyndaele
mesh_terms: D000344:Afferent Pathways; D000375:Aging / Q000502:physiology*; D000818:Animals; D004958:Estradiol / Q000097:blood*; D004967:Estrogens / Q000097:blood* / Q000172:deficiency; D005260:Female; D009413:Nerve Fibers, Myelinated; D036421:Nerve Fibers, Unmyelinated; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D001743:Urinary Bladder / Q000294:innervation / Q000502:physiology; D014554:Urination / Q000502:physiology*
chemical_list: D004967:Estrogens; D004958:Estradiol