5-Hydroxytryptamine-induced potentiation of cholinergic responses to electrical field stimulation in pig detrusor muscle.

摘要: Objective To determine whether detrusor muscle from the pig can be used as a model to study presynaptic 5-hydroxytryptamine (HT)4-receptor-mediated effects on electrical field stimulated (EFS) cholinergic responses previously identified in human bladder. Materials and methods Strips of were mounted physiological Krebs' solution under 1 g tension (25 Hz, 0.01 ms duration, 60 V for 5 s) at 100-s intervals allowed equilibrate. Concentration-response curves 5-HT (1 nmol/L 300 µmol/L) constructed presence absence 5-HT4-selective antagonists RS-100235 GR-113808 (both 0.3, 1 3 nmol/L). All experiments conducted methiothepin ondansetron 1 µmol/L) block 5-HT1, -HT2 -HT3 receptors. Results potentiated EFS bladder strips concentration-dependent manner, with maximum mean ( sem) potentiation 48.3 (7.7)% resting (n = 25). BothRS-100235 antagonized effect high affinity, yielding apparent pKB values which consistent being mediated via 5-HT4 receptor subtype. Conclusion These data indicate that potentiate isolated subtype mediates this response. Therefore, may an effective receptors reported bladder.