title: How antepartum and postpartum acute urinary retention affects the function and structure of the rat bladder.
abstract: OBJECTIVE
  To examine the effect of acute urinary retention (AUR) on the urodynamic function and molecular structure of rat bladders in pregnancy and after parturition.
  
  
  METHODS
  Forty-eight nulliparous rats were distributed into AUR and non-AUR groups. AUR was induced by clamping the distal urethra of each rat after infusing 3 ml of saline for 60 min. Plasma progesterone levels and cystometric data were evaluated on the 14th day of gestation, 3 and 10 days postpartum, and in virgin rats. The immunoreactivity of caveolins and nerve growth factor (NGF) was analyzed. The number of caveolae in bladder muscle cells was evaluated by electron microscopy.
  
  
  RESULTS
  Progesterone levels significantly increased during pregnancy and 3 days postpartum. In cystometric results, the AUR group has significantly shorter intercontraction interval, lower void volume and greater residual volume compared with the non-AUR. AUR rats exhibited higher NGF immunoreactivity, lower caveolin-1 immunoreactivity, and less caveolae in the bladder compared with the non-AUR. The caveolin-1 and NGF immunoreactivity and the number of caveolae in the bladder decreased during pregnancy and 3 days postpartum compared with virgin rats. By using Pearson correlations, we found significant correlations between urodynamic variables (residual volumes and intercontraction intervals) and the expressions of caveolin-1, caveolae and NGF in the AUR rats on the 14th day of gestation and 3 days postpartum.
  
  
  CONCLUSIONS
  Bladder dysfunction in pregnancy and immediately postpartum in a rat model caused by AUR is associated with the plasma progesterone level change and the expressions of caveolin, caveolae, and NGF in bladder muscle cells.
authors: Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Linkou Medical Center, 5, Fu-Shin Street, Kweishan, Taoyuan, Taiwan, Republic of China, 333, ccjoliang@cgmh.org.tw.
authors: Ching-Chung
authors: CC
authors: Liang
authors: Yi-Hao
authors: YH
authors: Lin
authors: Tse-Ching
authors: TC
authors: Chen
authors: Shuenn-Dhy
authors: SD
authors: Chang
mesh_terms: D000818:Animals; D021941:Caveolae / Q000648:ultrastructure; D051242:Caveolin 1 / Q000032:analysis; D005260:Female; D020932:Nerve Growth Factor / Q000032:analysis; D049590:Postpartum Period; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D001743:Urinary Bladder / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure*; D016055:Urinary Retention / Q000503:physiopathology*; D014563:Urodynamics
chemical_list: C495537:Cav1 protein, rat; D051242:Caveolin 1; D011374:Progesterone; D020932:Nerve Growth Factor