title: The role of the peripheral cannabinoid system in the pathogenesis of detrusor overactivity evoked by increased intravesical osmolarity in rats.
abstract: The cannabinoid receptors CB1 and CB2 are localized in the urinary bladder and play a role in the regulation of its function. We investigated the pathomechanisms through which hyperosmolarity induces detrusor overactivity (DO). We compared urinary bladder activity in response to blockade of CB1 and CB2 receptors using AM281 and AM630, respectively, in normal rats and after hyperosmolar stimulation. Experiments were performed on 44 rats. DO was induced by intravesical instillation of hyperosmolar saline. Surgical procedures and cystometry were performed under urethane anaesthesia. The measurements represent the average of 5 bladder micturition cycles. We analysed basal, threshold, and micturition voiding pressure; intercontraction interval; compliance; functional bladder capacity; motility index; and detrusor overactivity index. The blockage of CB1 and CB2 receptors diminished the severity of hyperosmolar-induced DO. In comparison with naïve animals the increased frequency of voiding with no significant effect on intravesical voiding pressure profile was observed as a result of the blockage of CB1 and CB2 receptors. These results demonstrate that hyperosmolar-induced DO is mediated by CB1 and CB2 receptors. Therefore, the cannabinoid pathway could potentially be a target for the treatment of urinary bladder dysfunction.
authors.affiliation: a Department of Urology, Ludwik Rydygier Memorial Hospital, Złotej Jesieni 1, 31-826 Cracow, Poland.|b Department of Pathophysiology, Jagiellonian University, Medical College, Cracow, Poland.
authors.forename: Kajetan
authors.initials: K
authors.lastname: Juszczak
authors.affiliation: a Department of Urology, Ludwik Rydygier Memorial Hospital, Złotej Jesieni 1, 31-826 Cracow, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Maciukiewicz
mesh_terms: D000283:Administration, Intravesical; D000818:Animals; D063387:Cannabinoid Receptor Antagonists / Q000494:pharmacology; D002186:Cannabinoids / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D007211:Indoles / Q000494:pharmacology; D009025:Morpholines / Q000494:pharmacology; D009994:Osmolar Concentration; D011720:Pyrazoles / Q000494:pharmacology; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D043885:Receptor, Cannabinoid, CB2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage; D015398:Signal Transduction; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D053201:Urinary Bladder, Overactive / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology / Q000517:prevention & control; D014554:Urination; D014563:Urodynamics
chemical_list: D063387:Cannabinoid Receptor Antagonists; D002186:Cannabinoids; C543264:Cnr1 protein, rat; C469526:Cnr2 protein, rat; D007211:Indoles; D009025:Morpholines; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D012462:Saline Solution, Hypertonic; C109925:AM 281; C094023:iodopravadoline
keywords: CB1; CB2; cannabinoid receptor; cystometry; cystométrie; detrusor overactivity; hyperactivité du détrusor; osmolarity; osmolarité; rat; récepteur cannabinoïde