Enhanced Neurogenic Activity And Nerve Density In Smooth Muscle Strips Taken From Closer To The Serosal Side Of The Human And Dog Bladder

You have accessJournal of UrologyBladder & Urethra: Anatomy, Physiology & Pharmacology (MP08)1 Sep 2021MP08-11 ENHANCED NEUROGENIC ACTIVITY AND NERVE DENSITY IN SMOOTH MUSCLE STRIPS TAKEN FROM CLOSER TO THE SEROSAL SIDE OF THE HUMAN AND DOG BLADDER Nagat Frara, Mary F. Barbe, Dania Giaddui, Alan S. Braverman, Lucas J. Hobson, Geneva E. Cruz, Mamta Amin, and Michael R. Ruggieri Nagat FraraNagat Frara More articles by this author , Mary F. BarbeMary F. Barbe More articles by this author , Dania GiadduiDania Giaddui More articles by this author , Alan S. BravermanAlan S. Braverman More articles by this author , Lucas J. HobsonLucas J. Hobson More articles by this author , Geneva E. CruzGeneva E. Cruz More articles by this author , Mamta AminMamta Amin More articles by this author , and Michael R. RuggieriMichael R. Ruggieri More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001981.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: In normal dog and human bladders, we aimed to investigate regional variations in muscle strip responses to different neurogenic and myogenic stimulations; with the assumption that smooth muscle of the bladder has similar contractile properties throughout the bladder wall thickness. METHODS: Bladders were harvested from seven normal male dogs and another three were obtained from human organ transplant donors; one male and two females. Smooth muscle strips were dissected from the dorsal and the ventral aspects of the body of the bladder at least 1 cm above the ureteral orifices. Mucosa was removed and strips were dissected from adjacent to the mucosa and separate strips from adjacent to the serosa. Maximal responses to electric field stimulation (EFS) and 120 mM potassium chloride (KCl) were determined. After washing and re-equilibration, responses to 30μM of the muscarinic receptor agonist bethanechol were determined. At the end of each experiment, strips were collected, fixed and stained for the axonal marker protein gene product 9.5 (PGP9.5) to assess axonal density. RESULTS: In dog bladders, strips from adjacent to the serosa showed more expression of PGP9.5 and greater axon density, than the strips from close to the mucosa. While EFS-induced contractions were significantly increased in the sub-serosal strips from dog bladders, compared to sub-mucosal strips, responses to EFS were not different between the sub-mucosal and sub-serosal strips from human bladders. In dog bladders, muscle contractions induced by either KCl or bethanechol were greater in strips adjacent to the mucosa than strips dissected immediately beneath the serosa. However, in human bladders, responses to KCl or bethanechol were similar in strips from either the mucosal or the serosal side. CONCLUSIONS: Much of the previous literature on contractile responses of bladder muscle strips incorporates the implicit assumption that strips from the dorsal versus ventral aspects and across the thickness of the bladder respond similarly to pharmacological agents. We observed for the first time that in dog bladder, the contractile responses to neurogenic and myogenic stimulators were different in muscle strip taken from close to the lumen than in strips taken from closer to the outer surface. The increase in the density of nerves in the smooth muscle that is closer to the outer surface of the bladder suggesting higher numbers of intramural axons. This finding may have important implications in the understanding of the physiology and biophysics of bladder emptying. Source of Funding: NINDS R01NS070267 © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e154-e154 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nagat Frara More articles by this author Mary F. Barbe More articles by this author Dania Giaddui More articles by this author Alan S. Braverman More articles by this author Lucas J. Hobson More articles by this author Geneva E. Cruz More articles by this author Mamta Amin More articles by this author Michael R. Ruggieri More articles by this author Expand All Advertisement Loading ...