121 UROTHELIAL DYSFUNCTION AND BLADDER OVERSENSITIVITY IN A RAT MODEL OF METABOLIC SYNDROME

Abstract

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Basic Research II1 Apr 2012121 UROTHELIAL DYSFUNCTION AND BLADDER OVERSENSITIVITY IN A RAT MODEL OF METABOLIC SYNDROME Wei-Chia Lee and Yao-Chi Chuang Wei-Chia LeeWei-Chia Lee Kaohsiung, Taiwan More articles by this author and Yao-Chi ChuangYao-Chi Chuang Kaohsiung, Taiwan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.169AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES We studied the role of urothelial dysfunction on bladder oversensitivity in rats with metabolic syndrome. METHODS Female Wistar rats were fed a fructose-rich diet (60%) or a normal diet for 3 months. Based on cystometry, the fructose-fed rats (FFRs) were divided into a group with normal detrusor function or detrusor overactivity (DO). Acidic adenosine triphosphate (ATP) solution (5mM, pH 3.3) was used to elicit reflex micturition. Cystometric parameters were evaluated before and after drug administration. Functional proteins of the urothelium were assessed by western blotting. RESULTS Compared to the controls, intravesical acidic ATP solution instillation induced a significant increase in provoked phasic contractions in both FFR groups and a significant decrease in the mean bladder capacity of group DO. Pretreatment with capsaicin for C-fiber desentization, intravesical liposome for mucosal protection, or intravenous pyridoxal 5-phosphate 6-azophenyl-2ꜟ,4ꜟ-disulfonic acid for antagonized purinergic receptors can interfere with the urodynamic effects of intravesical ATP in FFRs and controls. Over-expression of TRPV1, P2X3, and iNOS proteins, and down-regulation of eNOS proteins were observed in the urothelium of both fructose-fed groups. CONCLUSIONS Urothelial dysfunction, including over-expression of TRPV1, P2X3, and iNOS proteins, can precipitate the emergence of bladder phasic contractions and oversensitivity through the activation of C-afferents during acidic ATP solution stimulation in FFRs. The down-regulation of eNOS protein in the urothelium of FFRs may lead to a failure to suppress bladder oversensitivity and phasic contractions. Urothelial dysfunction and DO causing by metabolic syndrome are easier to elicit bladder oversensitivity to certain urothelium stimuli. Table 1. Comparisons of general characteristics, biochemistry variables, and cystometric parameters among controls and FFRs. Controls FFRs with NDF FFRs with DO (n=12) (n=12) (n=12) General characteristics Body weight (g) 276.4±6.6 295.6±13.3 290.1±8.9 Bladder weight (mg) 111.6±3.8 105.2±5.2 114.8±3.9 Waist circumference (cm) 16.9±0.22 17.4±0.27 18.2±0.27⁎ Systolic pressure (mmHg) 123.6±4.1 150.1±4.6⁎ 153.1±6.3⁎ Water intake 31.3±2.49 34.9±2.35 32.9±1.79 Urine output (ml/ 24hrs) 26.6±2.2 31.2±2.1 29±2.6 Biochemistry parameters (fasting values) Triglycerides (mg/dl) 34.3±2.5 86.1±4.8⁎ 81.3±6.9⁎ Cholesterol (mg/dl) 45.7±2.3 66.6±3.4⁎ 64.8±3.5⁎ Glucose (mM) 6.6±0.19 7.3±0.39 7.0±0.28 Insulin (mU/l) 13.9±0.69 24.2±1.94⁎ 22.2±1.71⁎ †HOMA-IR 4.1±0.27 7.7±0.65⁎ 6.9±0.53⁎ Cystometry parameters Before treatment Voiding pressure (mmHg) 21.5±0.9 21.8±1.2 25.0±1.1 Bladder capacity (ml) 1.19±0.04 1.17±0.03 0.95±0.06⁎ After 5mM ATP instillation Voiding pressure (mmHg) 22.3±1.1 23.1±1.2 27.7±1.4⁎ Voiding pressure increase (mmHg) 0.78±0.49 1.27±0.54 2.74±0.46⁎ Bladder capacity (ml) 0.89±0.08 0.79±0.04 0.52±0.04⁎ Lessened bladder capacity (%) 26.0±4.6 32.9±2 46.2±2.1⁎ No. provoked phasic contraction (> 15 cmH2O) per void 0.9±0.21 3.3±0.4⁎ 2.1±0.27⁎ Immunofluorescence stain of the bladder Nerve fiber density of suburothelium (Number per cross-section of bladder base) 537.7±36.2 489.5±40.4 578.5±31.4 Data presented as mean ± SEM and tested among groups using one-way ANOVA with Dunnett's test. ⁎ The Dunnett's test showed a significant difference between the control group and other groups. † Homeostasis model assessment of insulin resistance (HOMA-IR) =fasting plasma insulin (μU/ml) × fasting plasma glucose (mmol/l)/22.5. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e49-e50 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Wei-Chia Lee Kaohsiung, Taiwan More articles by this author Yao-Chi Chuang Kaohsiung, Taiwan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...