2056 PROPAGATION OF THE ELECTRICAL IMPULSE IN REVERSIBLE UNILATERAL URETERAL OBSTRUCTION AS DETERMINED AT HIGH ELECTROPHYSIOLOGICAL RESOLUTION

Abstract

You have accessJournal of UrologyStone Disease: Basic Research1 Apr 20112056 PROPAGATION OF THE ELECTRICAL IMPULSE IN REVERSIBLE UNILATERAL URETERAL OBSTRUCTION AS DETERMINED AT HIGH ELECTROPHYSIOLOGICAL RESOLUTION Fayez Hammad, Wim Lammers, Betty Stephen, and Loay Lubbad Fayez HammadFayez Hammad Al Ain, United Arab Emirates More articles by this author , Wim LammersWim Lammers Al Ain, United Arab Emirates More articles by this author , Betty StephenBetty Stephen Al Ain, United Arab Emirates More articles by this author , and Loay LubbadLoay Lubbad Al Ain, United Arab Emirates More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.2287AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Several studies have shown that ureteral obstruction results in alterations in ureteral functions including the peristaltic activities and propagation of electrical impulses along the ureter. However, there is no data on the alterations in the ureteral electrical activities following partial or complete reversible ureteral obstruction. Reconstruction of the spatial and temporal pattern of electrical activities by recording simultaneously from a large number of extracellular sites is a relatively new technique that has been used to study the electrical activities in various organs. Therefore, the aim of this study was to investigate the electrical propagation of electrical impulses in a reversible unilateral ureteral (complete or partial) obstruction model in vivo. METHODS In Wistar rats, the left midureter was completely (n=8) or partially (n=7) occluded and released after 24 hours. The electrical activities of the left and right ureter were recorded before, during and after obstruction at different stages up to 2 weeks post-obstruction using a high resolution 64 extracellular electrode probe (16x4 array; inter-electrode distance 0.3mm) which was carefully positioned on the surface of the ureter. RESULTS Complete obstruction caused an immediate increase in frequency of the electrical impulses (from 14.8±1.3 to 18.6±1.7/min, P<0.05) in the left proximal ureter followed by a decrease (1.4±0.9/min; P<0.001) while the velocity gradually decreased (from 1.82±0.12 to 0.79±0.17 cm/sec; P<0.001) within the first 2 days post-reversal. Release of the obstruction gradually restored frequency and velocity, which returned to basal values after 2 weeks. Generally, the alterations in complete and partial obstructions were similar although they were less marked in partial obstruction. Distal to the obstruction site, the impulses either disappeared (38%) or propagated retrogradely (43%) at some stage in the post-obstruction period. These abnormal impulse propagations also gradually disappeared in the post-obstruction stage. CONCLUSIONS Following complete or partial ureteral obstruction, there were immediate and significant changes in the propagation of electrical impulses in the proximal and distal left ureter. These alterations were generally less marked following partial compared to complete obstruction. Reversal of the obstruction resulted in the gradual disappearance of these abnormalities in two weeks. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e823 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Fayez Hammad Al Ain, United Arab Emirates More articles by this author Wim Lammers Al Ain, United Arab Emirates More articles by this author Betty Stephen Al Ain, United Arab Emirates More articles by this author Loay Lubbad Al Ain, United Arab Emirates More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...