Cause of Residual Urine in Bladder Outlet Obstruction: An Experimental Study in the Rat
2012 (English)In: Journal of Urology, ISSN 0022-5347, E-ISSN 1527-3792, Vol. 188, no 3, 1027-1032 p.Article in journal (Refereed) Published
Purpose: We explored the role of bladder mechanoreceptors in post-void residual urine in rats with bladder outlet obstruction. less thanbrgreater than less thanbrgreater thanMaterials and Methods: Partial bladder outlet obstruction was induced by a urethral ligature in 11 adult female Sprague-Dawley (R) rats. Nine sham operated rats served as controls. The outcome was evaluated in acute experiments using alpha-chloralose anesthesia 6 weeks later. Bladders were catheterized for infusion, pressure recording and intravesical electrical stimulation. Bladder efferent activity was recorded from a thin pelvic nerve branch close to the bladder. Micturition contractions were triggered at different bladder volumes by a brief train of electrical stimulation of bladder afferents while monitoring post-stimulus efferent activity and reflex bladder contractions. The degree of obstruction was assessed by bladder wet weight at the end of the experiment. less thanbrgreater than less thanbrgreater thanResults: Bladder weight, micturition threshold volume, anatomical bladder capacity and peak contraction force were significantly increased in obstructed rats. In sham operated controls a triggered micturition reflex was sustained by afferent feedback from the bladder until the bladder was empty. In contrast, reflex discharges failed with substantial volume remaining in the bladder in obstructed rats. The minimal micturition reflex volume correlated positively with bladder weight, micturition threshold volume and maximal bladder capacity (r andgt;= 0.74). less thanbrgreater than less thanbrgreater thanConclusions: In rats with partial bladder outlet obstruction the micturition reflex failed before the bladder was empty due to a decreased afferent drive from bladder mechanoreceptors. Similar changes may contribute to post-void residual urine in humans with bladder outlet obstruction.
Place, publisher, year, edition, pages
Elsevier , 2012. Vol. 188, no 3, 1027-1032 p.
urinary bladder, urinary bladder neck obstruction, reflex, mechanoreceptors, rats, Sprague-Dawley
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-84898DOI: 10.1016/j.juro.2012.04.101ISI: 000307551200114OAI: oai:DiVA.org:liu-84898DiVA: diva2:562931