The role of substance P in the human urinary bladder.
Detrusor muscle from human bladder contracted to field stimulation after atropine. It also responded to exogenous substance P by an atropine-insensitive mechanism. We tested whether substance P might mediate noncholinergic excitation. Tachyphylaxis to substance P did not effect noncholinergic responses to field stimulation. A substance P antagonist was ineffective in blocking responses to field stimulation or to exogenous substance P. Capsaicin had only nonspecific depressant effects on field stimulated contraction in high (10(-4) M) concentrations. These data do not support the hypothesis that substance P is the mediator of noncholinergic, field stimulated contractions of human detrusor muscle.
D001285:Atropine / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000502:physiology; D018377:Neurotransmitter Agents; D013373:Substance P / Q000502:physiology*; D001743:Urinary Bladder / Q000294:innervation / Q000502:physiology*
D018377:Neurotransmitter Agents; D013373:Substance P; D001285:Atropine; D002217:Carbachol; D002211:Capsaicin