MP28-15 EFFECTS OF SINGLE BOUT ACUTE INTERMITTENT HYPOXIA PROTOCOLS ON REFLEX MICTURITION IN NAIVE AND SPINAL CORD-INJURED ADULT RATS

Abstract

You have accessJournal of UrologyBladder & Urethra: Anatomy, Physiology & Pharmacology I (MP28)1 Apr 2020MP28-15 EFFECTS OF SINGLE BOUT ACUTE INTERMITTENT HYPOXIA PROTOCOLS ON REFLEX MICTURITION IN NAIVE AND SPINAL CORD-INJURED ADULT RATS William Collins*, Christine Wang, and Irene Solomon William Collins*William Collins* More articles by this author , Christine WangChristine Wang More articles by this author , and Irene SolomonIrene Solomon More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000867.015AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Acute intermittent hypoxia (AIH) has been suggested as a potential therapy in spinal cord injury (SCI) since it can induce neural plasticity in both respiratory and non-respiratory somatic motor systems. Implementing the most commonly used AIH protocol consisting of a single bout of three 5-min episodes of hypoxia, we have previously demonstrated that AIH produces a sustained decrease in the frequency of reflex micturition events (rME) accompanied by an increase in micturition volume in both naïve rats and rats with moderate SCI as well as a sustained decrease in the frequency of non-voiding contractions in SCI rats. In the present study, we examine the effects of different single bout AIH protocols that keep the total duration of hypoxia (15 min) constant but differ in timing and number of hypoxic episodes on lower urinary tract (LUT) function in naïve and SCI rats. METHODS: We assessed the effects of three single bout AIH protocols on bladder intravesical pressure (BP) and void volume recorded under urethane anesthesia (1.4 g/kg) in naïve and mid-thoracic moderate contusion SCI (4-week survival) rats during continuous infusion of saline (0.04 ml/min) into the bladder to elicit rMEs. The AIH protocols implemented consisted of alternating exposures of hypoxia (12% O2) and normoxia using the following: (1) three 5-min episodes, (2) five 3-min episodes, and (3) ten 1.5-min episodes. Following the AIH exposure, data acquisition continued for up to 120 minutes while the rats continued to breathe room air. RESULTS: In both naïve and SCI rats, each single bout AIH protocol produced a comparable decrease in rME frequency and increase in void volume that persisted for up 120 min post-AIH. Moreover, in SCI rats, each of the protocols was equally effective in reducing the ratio of non-voiding/voiding bladder contractions. Single bout AIH exposure also produced transient increases in both bladder contraction threshold BP and minimum BP. Modulation of LUT behavior during individual exposures to hypoxia and immediately following each hypoxic episode (“off effect”) were also observed, with the intensity of the “off effect” tending to be lower following short duration (e.g., 10 x 1.5-min) hypoxic exposures. CONCLUSIONS: Our observations suggest that while each single bout AIH protocol is effective in improving micturition and reducing non-voiding bladder contractions in SCI rats, subtle differences in magnitude and/or timing were noted across the protocols. Source of Funding: DOD CDMRP W81XWH-17-1-0260; NIH NS096514 © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e425-e426 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information William Collins* More articles by this author Christine Wang More articles by this author Irene Solomon More articles by this author Expand All Advertisement PDF downloadLoading ...