Further studies on the mechanisms responsible for the neurokinin-induced activation of micturition reflex in rats: evidence for the involvement of the capsaicin-sensitive bladder mechanoreceptors.

The relative ability of mammalian and non-mammalian tachykinins to activate the rat micturition reflex was investigated. Neither a direct action on muscle cells nor a potentiating effect on efferent neurotransmission can account for the rank order of potency of the different tachykinins for activation of the reflex. Further evidence is drawn that the integrity of the capsaicin-sensitive bladder mechanoreceprors is essential, indicating that an NKB receptor, possibly on sensory nerves in the bladder wall, participates in the TK-induced activation of micturition reflex.