title: Neural mechanisms of impaired micturition reflex in rats with acute partial bladder outlet obstruction.
abstract: To determine the contribution of neural elements to micturition, we evaluated, in intact rats, the cystometrogram, pelvic afferent nervous activity, pelvic efferent nervous activity and external urethral sphincter-electromyogram activity in the normal and acute partial bladder outlet obstruction states. In the normal state, in response to saline filling, mechanoreceptor-dependent pelvic afferent nervous activity gradually activated and finally triggered a voiding reflex, including four phases of detrusor contractions. Phase 1 was characterized by an initial rising intravesical pressure, Phase 2 was characterized by a series of high-frequency oscillations in intravesical pressure, Phase 3 contraction was characterized by a rebound intravesical pressure and Phase 4 contraction was characterized by a rapid fall in intravesical pressure. In the acute partial bladder outlet obstruction state, Phase 1 contraction rose and high-frequency oscillations fell in Phase 2. This voiding dysfunction is ascribed to the bursting extraurethral sphincter activity being converted to tonic extraurethral sphincter activity. In summary, the suppressed high-frequency oscillations in Phase 2 of the detrusor muscle contraction could be detrimental to efficient voidings in the acute partial bladder outlet obstructed rat.
authors.affiliation: Departments of Clinical Research and Physiology, College of Medicine, National Taiwan University, Jen-Ai Rd, Taipei, Taiwan.
authors.forename: C T
authors.initials: CT
authors.lastname: Chien
authors.forename: H J
authors.initials: HJ
authors.lastname: Yu
authors.forename: T B
authors.initials: TB
authors.lastname: Lin
authors.forename: C F
authors.initials: CF
authors.lastname: Chen
mesh_terms: D000208:Acute Disease; D000244:Adenosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004338:Drug Combinations; D004576:Electromyography; D005260:Female; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009420:Nervous System / Q000503:physiopathology*; D009475:Neurons, Afferent / Q000502:physiology; D009476:Neurons, Efferent / Q000502:physiology; D018733:Nicotinic Antagonists / Q000494:pharmacology; D010388:Pelvis / Q000294:innervation; D051381:Rats; D017208:Rats, Wistar; D012018:Reflex; D014403:Tubocurarine / Q000494:pharmacology; D014521:Urethra / Q000503:physiopathology; D001743:Urinary Bladder / Q000187:drug effects / Q000503:physiopathology; D001748:Urinary Bladder Neck Obstruction / Q000503:physiopathology*; D014554:Urination
chemical_list: D004338:Drug Combinations; D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists; C523965:alpha,beta-methyleneadenosine 5'-diphosphate; D000244:Adenosine Diphosphate; D001285:Atropine; D014403:Tubocurarine