title: Local Change in Urinary Bladder Contractility Following CNS Dopamine Denervation in the 6-OHDA Rat Model of Parkinson's Disease.
abstract: BACKGROUND
  Urinary problems, including urinary frequency, urgency, and nocturia are some of the non-motor symptoms that correlate most with poor quality of life in Parkinson's disease. However, the mechanism behind these symptoms is poorly understood, in particular regarding peripheral bladder pathophysiology following dopamine degeneration.
  
  
  OBJECTIVE
  In this study, we compared the contractile responsiveness of urinary bladder from the 6-OHDA unilateral rat model of Parkinson's disease with that of normal untreated animals.
  
  
  METHODS
  The contractility of the urinary detrusor muscle was evaluated in bladder strip preparations using electrical field stimulation, and muscarinic and purinoceptor stimulations in an vitro organ bath setup.
  
  
  RESULTS
  Our data show that the overall contractile response following electrical field stimulation was significantly higher (43% at maximum contraction by 20-40 Hz stimulation) in the 6-OHDA-lesioned rats as compared to control animals. This increase was associated with a significant increase in the cholinergic contractile response, where the muscarinic agonist methacholine produced a 44% (at 10 -4 M concentration) higher response in the 6-OHDA-treated rats as compared to controls with a significant left-shift of the dose response. This indicates an altered sensitivity of the muscarinic receptor system following the specific central 6-OHDA-induced dopamine depletion. In addition a 36% larger contraction of strips from the 6-OHDA animals was also observed with purinoceptor activation using the agonist ATP (5×10 -3 M) during atropine treatment.
  
  
  CONCLUSIONS
  Our data shows that it is not only the central dopamine control of the micturition reflex that is altered in Parkinson's disease, but also the local contractile function of the urinary bladder. The current study draws attention to a mechanism of urinary dysfunction in Parkinson's disease that has previously not been described.
authors.forename: Reinika
authors.initials: R
authors.lastname: Mitra
authors.forename: Patrik
authors.initials: P
authors.lastname: Aronsson
authors.forename: Michael
authors.initials: M
authors.lastname: Winder
authors.forename: Gunnar
authors.initials: G
authors.lastname: Tobin
authors.forename: Filip
authors.initials: F
authors.lastname: Bergquist
authors.forename: Thomas
authors.initials: T
authors.lastname: Carlsson
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000473:pathology; D003714:Denervation; D004195:Disease Models, Animal; D059290:Dopaminergic Neurons / Q000187:drug effects / Q000473:pathology; D004558:Electric Stimulation; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology; D018721:Muscarinic Agonists / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D016627:Oxidopamine; D020734:Parkinsonian Disorders / Q000139:chemically induced / Q000503:physiopathology*; D058905:Purinergic Agents / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D001743:Urinary Bladder / Q000187:drug effects / Q000503:physiopathology*
chemical_list: D018721:Muscarinic Agonists; D058905:Purinergic Agents; D016210:Methacholine Chloride; D016627:Oxidopamine; D000255:Adenosine Triphosphate
keywords: Urinary bladder pathophysiology; detrusor muscle; muscarinic receptor; parasympathetic nervous system