title: The effect of bladder outlet obstruction on tissue oxygen tension and blood flow in the pig bladder.
abstract: OBJECTIVE
  To investigate the effect of partial bladder outlet obstruction on detrusor blood flow and oxygen tension (PdetO2) in female pigs.
  
  
  METHODS
  Detrusor-layer oxygen tension and blood flow were measured using oxygen-sensitive electrode and radiolabelled microsphere techniques in five female Large White pigs with a partial urethral obstruction and in five sham-operated controls. The effects of chronic outlet obstruction on bladder weight, and cholinergic nerve density and distribution, are also described.
  
  
  RESULTS
  In the obstructed bladders, blood flow and oxygen tension were, respectively, 54.9% and 74.3% of control values at low bladder volume, and 47.5% and 42.5% at cystometric capacity. Detrusor blood flow declined by 27.8% and 37.5% in the control and obstructed bladders, respectively, as a result of bladder filling, whilst PdetO2 did not decrease in the controls, but fell by 42.7% in the obstructed bladders. Bladder weight increased whilst cholinergic nerve density decreased in the obstructed animals.
  
  
  CONCLUSIONS
  In pigs with chronic bladder outlet obstruction, blood flow and oxygen tension in the detrusor layer were lower than in control animals. In addition, increasing detrusor pressure during filling caused significantly greater decreases in blood flow and oxygen tension in the obstructed than in the control bladders.
authors.affiliation: Department of Urology, Churchill Hospital, Oxford, Institute of Experimental Clinical Research, Skejby University Hospital, Aarhus, Denmark. jon@jgreenland.enterprise-plc.com
authors.forename: J E
authors.initials: JE
authors.lastname: Greenland
authors.forename: J J
authors.initials: JJ
authors.lastname: Hvistendahl
authors.forename: H
authors.initials: H
authors.lastname: Andersen
authors.forename: T M
authors.initials: TM
authors.lastname: Jörgensen
authors.forename: G
authors.initials: G
authors.lastname: McMurray
authors.forename: M
authors.initials: M
authors.lastname: Cortina-Borja
authors.forename: A F
authors.initials: AF
authors.lastname: Brading
authors.forename: J
authors.initials: J
authors.lastname: Frøkiaer
mesh_terms: D000818:Animals; D003250:Constriction; D005260:Female; D007511:Ischemia / Q000503:physiopathology; D010100:Oxygen / Q000032:analysis*; D010313:Partial Pressure; D013552:Swine; D014524:Urethral Obstruction / Q000503:physiopathology*; D001743:Urinary Bladder / Q000098:blood supply* / Q000737:chemistry; D001748:Urinary Bladder Neck Obstruction / Q000503:physiopathology*
chemical_list: D010100:Oxygen