Overactive bladder--experimental aspects.
Supra-pontine lesions resulting from neurological disorders such as vascular disease, Parkinson's disease, or Alzheimer type senile dementia lead to an increase in bladder activity. This is due in part to the removal at the cortical inhibitory control of the micturition center in the brain stem - i.e. the pontine micturition center (PMC) - and in part to facilitation of excitatory control. These inhibitory or excitatory controls consist of several neurotransmitter systems, including glutamate, dopamine, gamma-aminobutyric acid (GABA), and acetylcholine. Bladder overactivity caused by cerebral infarction is mediated by upregulation of N-methyl-D-aspartate (NMDA) glutamatergic and D2 dopaminergic excitatory mechanisms, and by downregulation of NMDA glutamatergic and Ml muscarinic inhibitory mechanisms in the brain. Bladder overactivity associated with Parkinson's disease is reportedly induced by a loss of input to the D1 dopaminergic receptor. Furthermore, bladder overactivity caused by Alzheimer type dementia is thought to be mediated by downregulation of M1 muscarinic inhibitory mechanisms. Development of bladder overactivity following cerebral infarction is mediated by activation of the NMDA receptor and accompanied by an increase in c-fos, zif268 and COX-2 mRNA expression in the dorsal pontine tegmentum.
Yokoyama
Osamu
O
Department of Urology, Kanazawa University School of Medicine, Japan. oyoko@fmsrsa.fukui-med.ac.jp
Komatsu
Kazuto
K
Ishiura
Yoshiyuki
Y
Akino
Hironobu
H
Kodama
Koichi
K
Yotsuyanagi
Satoshi
S
Moriyama
Norihiro
N
Nagasaka
Yasuhiro
Y
Ito
Yasuhiko
Y
Namiki
Mikio
M
D000818:Animals; D002545:Brain Ischemia / Q000503:physiopathology; D018377:Neurotransmitter Agents / Q000502:physiology; D011149:Pons / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011976:Receptors, Muscarinic / Q000502:physiology; D001750:Urinary Bladder, Neurogenic / Q000503:physiopathology*; D014554:Urination / Q000502:physiology
D018377:Neurotransmitter Agents; D011976:Receptors, Muscarinic