Evidence for a central monoaminergic influence on urinary bladder control mechanism.
The aim of the present study was to investigate a possible central monoaminergic influence on the control mechanism of the urinary bladder in rats. A selective central nervous stimulation was accomplished by injection of monoaminergic precursor (L-dopa and 5-HTP) after enzymatic blockade of its peripheral metabolisation. The bladder response was recorded with a cytometric procedure. The central adrenergic stimulation with L-dopa resulted in a hyperactive bladder response, with higher intravesical pressure and more prominent detrusor contractions than in control rats. Injection of 5-HTP had no such effect. The hyperactive bladder response to L-dopa was abolished by prior administration of a central dopamine receptor blocking agent (spiroperiodol). This indicated that the central effect on the bladder was elicited by dopaminergic structures. Peripheral adrenergic stimulation with metabolites of L-dopa--dopamine and noradrenaline--gave no measurable bladder response. The study showed that activation of central adrenergic mechanisms influenced urinary bladder control, i.e. evoked a hyperactive bladder response.
D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000818:Animals; D001545:Benserazide / Q000494:pharmacology; D001921:Brain / Q000187:drug effects*; D002230:Carbidopa / Q000494:pharmacology; D002395:Catecholamines / Q000494:pharmacology*; D004298:Dopamine / Q000494:pharmacology; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010275:Parasympathetic Nervous System / Q000502:physiology*; D011312:Pressure; D051381:Rats; D013134:Spiperone / Q000494:pharmacology; D001743:Urinary Bladder / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D014563:Urodynamics / Q000187:drug effects*
D002395:Catecholamines; D007980:Levodopa; D013134:Spiperone; D001545:Benserazide; D006916:5-Hydroxytryptophan; D002230:Carbidopa; D004298:Dopamine; D009638:Norepinephrine