|ITEM METADATA RECORD
|Title: ||Evidence for age-dependent changes in spontaneous contractility and its muscarinic regulation in rat bladder|
|Authors: ||Gevaert, Thomas|
De Ridder, Dirk #
|Issue Date: ||Mar-2007 |
|Publisher: ||Elsevier science bv|
|Host Document: ||European urology supplements vol:6 issue:2 pages:271-271|
|Conference: ||EAU edition:22 location:Berlin date:2007|
|Article number: ||995|
|Abstract: ||Introduction & Objectives:
It’s known that during postnatal development primitive bladder reflexes are steadily replaced by supraspinal mechanisms which underlie the mature bladder-tobladder
reflex and voluntary voiding1. Most research to explore the underlying mechanisms for these developmental changes in bladder contractility has been done on the neural pathways that innervate the bladder. However non-neural developmental changes in local bladder properties might also contribute to establish mature voiding reflexes. In the present study we looked at spontaneous contractility and the response to selective and non-selective muscarinic agonists in bladder strips from rats at different age (Day 0 (D0), D7, D28 and 6 weeks (W6)).
Material & Methods:
Bladders were dissected from rats at different age (D0, D7, D28, and W6) and processed to full bladder strips. These were attached to a pressure transducer and hung up in a heated and oxygenated organ bath, filled with Krebs solution. Spontaneous bladder contractions and their response to the non-selective muscarinic agonist carbachol and the M2-selective agonist arecaïdine were recorded and studied.
Spontaneous bladder contractions were absent at D0, but from D7 to W6, spontaneous contractions were observed with similar frequency and amplitude. However the contractile
duration was longer at D28 and W6. The most remarkable finding was the significant higher sensitivity to M2-agonists at D0 and D7 (p<0,05). M2-stimulation provoked a clear shift in pressure baseline and in contractile amplitude in D0 and D7 bladders, while in D28 and W6
M2-stimulation had few or no effect on these parameters. Moreover M2-stimulation induced an increase in contractile frequency, and this only in D7-bladders. The response to the nonselective carbachol (M2+M3) carbachol (shift in baseline and amplitude) was increasing with age, thus most pronounced at W6.
We found evidence for developmental, age-related changes in spontaneous bladder contractility, which might contribute to the onset of mature voiding reflexes. The present
data reveal that, with increasing age, the pattern of spontaneous bladder contractility changes and the muscarinic contractile regulation shifts from M2 to M3. These findings support the idea that local, non-neural changes might also be important in the development of mature voiding. Moreover, if M2 is validated in other species as the predominant muscarinic mediator of neonatal
contractions, it could be a new investigational target for the treatment of functional paediatric bladder disorders. References 1 de Groat WC, Araki I, Vizzard MA, Yoshiyama M, Yoshimura N, Sugaya K, Tai C, Roppolo JR. Developmental and injury induced plasticity in the micturition reflex pathway. Behav Brain Res 1998 May;92(2):127-40.
|Publication status: ||published|
|KU Leuven publication type: ||IMa|
|Appears in Collections:||Urology Section (-)|
Clinical Residents Medicine
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