title: Metabolic Syndrome Induced Bladder Cannabinoid Receptor Changes in the Fructose-Fed Rats.
abstract: OBJECTIVE
  To investigate the effect of metabolic syndrome on the bladder cannabinoid receptors 1 and 2 (CB1/CB2) expression and function in the fructose-fed rats (FR).
  
  
  METHODS
  Adult male Sprague-Dawley rats were divided into two groups: (i) Control rats fed with normal chow; and (ii) Rats fed with high-fructose diet (FR) for 9 weeks. The body weight, blood pressure, plasma sugar, insulin, triglyceride and cholesterol were measured. Bladder muscle strips were prepared in organ bath and pre-contracted with 1 µM/L acetylcholine (ACh) or 50 mM/L KCl. The relaxation responses to CB1/CB2 agonist Bay59-3047 (0.01-1 µM/L) were recorded. The effects of CB1 antagonist AM251, CB2 antagonist AM630, protein kinase A (PKA) inhibitor H-89 and ATP-sensitive potassium channel (KATP)inhibitor glibenclamide on the Bay59-3047-induced response were tested. Western blotting and real-time polymerase chain reaction (RT-PCR) analyses were performed for bladder CB1/CB2 receptors.
  
  
  RESULTS
  Significant increases of body weight, blood pressure, plasma glucose, insulin, cholesterol and triglyceride levels were found in the FR. Bay59-3047 reduced ACh and KCl pre-contracted bladder strip tension in a dose-dependent fashion. The relaxation responses were significantly decreased in the FR. The Bay59-3047-induced relaxation was attenuated by AM251, glibenclamide and H-89. Western blotting and RT-PCR showed decreased expressions of FR bladder CB1 and CB2 receptor protein and mRNA.
  
  
  CONCLUSIONS
  CB1/CB2 receptors mediate rat bladder relaxation through the PKA and KATPpathway. The CB1 receptor may play a more prominent role. The response is decreased in the FR bladder due to reduced expressions of the cannabinoid receptors.
authors.affiliation: Department of Urology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: I-Hung
authors.initials: IH
authors.lastname: Chen
authors.affiliation: Department of Medical Research, Chi-Mei Medical Center, Tainan, Taiwan.|Department of Pharmacology, Institute of Medical Sciences, Chang Jung Christian University, Tainan, Taiwan.
authors.forename: Juei-Tang
authors.initials: JT
authors.lastname: Cheng
authors.affiliation: Department of Urology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Yat-Ching
authors.initials: YC
authors.lastname: Tong
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D004032:Diet; D005632:Fructose / Q000008:administration & dosage; D008297:Male; D024821:Metabolic Syndrome / Q000503:physiopathology*; D009119:Muscle Contraction / Q000187:drug effects; D009125:Muscle Relaxants, Central / Q000494:pharmacology; D017207:Rats, Sprague-Dawley; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism / Q000502:physiology*; D043885:Receptor, Cannabinoid, CB2 / Q000378:metabolism / Q000502:physiology*; D001743:Urinary Bladder / Q000378:metabolism* / Q000502:physiology; D015430:Weight Gain / Q000502:physiology
chemical_list: D009125:Muscle Relaxants, Central; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D005632:Fructose
keywords: KATP channel; bladder; cannabinoid receptors; metabolic syndrome; protein kinase A