Michelle von Siebenthal1, Marc P Schneider1, Shaokai Zheng2, Patrick Y Wuethrich3, Fiona C Burkhard1,4, Katia Monastyrskaya1,4. 1. Urology Research Laboratory, Department for BioMedical Research DBMR, University of Bern Switzerland. 2. Urogenital Engineering Group, ARTORG Center, Faculty of Medicine, University of Bern Bern, Switzerland. 3. Department of Anaesthesiology and Pain Medicine, Inselspital University Hospital, University of Bern Bern, Switzerland. 4. Department of Urology, Inselspital University Hospital, University of Bern Bern, Switzerland.
Abstract
OBJECTIVE: We aimed to study the effects of anaesthetics on bladder function using repeated urodynamic investigation (UDI) including external urethral sphincter (EUS) electromyography (EMG) in awake restrained mice. MATERIALS AND METHODS: Female C57Bl/6J mice underwent either bladder catheter (n=6) or bladder catheter plus electrodes (n=10) implantation next to the EUS. A control group (n=3) was included for histological analysis. Following awake UDI, the effects of midazolam (5 mg/kg) and opioids (fentanyl (50 μg/kg) and hydromorphine (250 μg/kg)) on bladder function were studied. Mice were allowed to recover from drug application for at least one day before being subjected to the next drug and UDI. Bladder weight was assessed and fibrotic changes were analysed by Masson's trichrome staining. RESULTS: EUS-EMG activity during voiding was reduced compared to before and after voiding in baseline measurements. Threshold and maximal detrusor pressure were significantly increased in both midazolam and the opioids. The opioids lead to either a significantly increased bladder filling volume and micturition cycle duration (hydromorphine) or a complete loss of the voiding phase leading to overflow incontinence (fentanyl). Bladder-to bodyweight ratio was significantly increased in both groups with an implanted catheter compared to controls. No differences were observed between the groups with- or without implanted electrodes regarding bladder-to bodyweight ratio, bladder fibrosis and urodynamic parameters. CONCLUSIONS: Repeated UDIs combined with EUS-EMG are feasible in the awake mouse model. The presence of electrodes next to the EUS does not obstruct the bladder outlet. Opioids and benzodiazepines severely interfere with physiological bladder function: fentanyl and hydromorphine disrupted the voiding phase evidenced by the reduced coordination of EUS activity with detrusor contraction, while bladder emptying under midazolam was achieved by EUS relaxation only. AJCEU
OBJECTIVE: We aimed to study the effects of anaesthetics on bladder function using repeated urodynamic investigation (UDI) including external urethral sphincter (EUS) electromyography (EMG) in awake restrained mice. MATERIALS AND METHODS: Female C57Bl/6J mice underwent either bladder catheter (n=6) or bladder catheter plus electrodes (n=10) implantation next to the EUS. A control group (n=3) was included for histological analysis. Following awake UDI, the effects of midazolam (5 mg/kg) and opioids (fentanyl (50 μg/kg) and hydromorphine (250 μg/kg)) on bladder function were studied. Mice were allowed to recover from drug application for at least one day before being subjected to the next drug and UDI. Bladder weight was assessed and fibrotic changes were analysed by Masson's trichrome staining. RESULTS: EUS-EMG activity during voiding was reduced compared to before and after voiding in baseline measurements. Threshold and maximal detrusor pressure were significantly increased in both midazolam and the opioids. The opioids lead to either a significantly increased bladder filling volume and micturition cycle duration (hydromorphine) or a complete loss of the voiding phase leading to overflow incontinence (fentanyl). Bladder-to bodyweight ratio was significantly increased in both groups with an implanted catheter compared to controls. No differences were observed between the groups with- or without implanted electrodes regarding bladder-to bodyweight ratio, bladder fibrosis and urodynamic parameters. CONCLUSIONS: Repeated UDIs combined with EUS-EMG are feasible in the awake mouse model. The presence of electrodes next to the EUS does not obstruct the bladder outlet. Opioids and benzodiazepines severely interfere with physiological bladder function: fentanyl and hydromorphine disrupted the voiding phase evidenced by the reduced coordination of EUS activity with detrusor contraction, while bladder emptying under midazolam was achieved by EUS relaxation only. AJCEU
Authors: Marc P Schneider; Andrea M Sartori; Juliane Tampé; Selina Moors; Anne K Engmann; Benjamin V Ineichen; Anna-Sophie Hofer; Martin E Schwab; Thomas M Kessler Journal: Neurourol Urodyn Date: 2017-11-15 Impact factor: 2.696
Authors: Hiroki Ito; Anthony E Pickering; Yasuhiko Igawa; Anthony J Kanai; Christopher H Fry; Marcus J Drake Journal: Front Physiol Date: 2017-02-06 Impact factor: 4.566