Authors: Mitsuharu Yoshiyama William C de Groat
Publish Date: 2008/08/02
Volume: 36, Issue: 1-3, Pages: 227-240
Abstract
Vasoactive intestinal polypeptide VIP and pituitary adenylate cyclaseactivating polypeptide PACAP are expressed in the neural pathways regulating the lower urinary tract VIPimmunoreactivity IR is present in afferent and autonomic efferent neurons innervating the bladder and urethra whereas PACAPIR is present primarily in afferent neurons Exogenously applied VIP relaxes bladder and urethral smooth muscle and excites parasympathetic neurons in bladder ganglia PACAP relaxes bladder and urethral smooth muscle in some species pig but excites the smooth muscle in other species mouse Intrathecal administration of VIP in cats with an intact spinal cord suppresses reflex bladder activity but intrathecal administration of VIP or PACAP in rats enhances bladder activity and suppresses urethral sphincter activity PACAP has presynaptic facilitatory effects and direct excitatory effects on lumbosacral parasympathetic preganglionic neurons Chronic spinal cord transection produces an expansion of VIPIR cats and PACAPIR rats in primary afferent axons in the lumbosacral spinal cord and unmasks spinal excitatory effects of VIP on bladder reflexes in cats Intrathecal administration of PACAP638 a PAC1 receptor antagonist reduces bladder hyperactivity in chronic spinalcordinjured rats These observations raise the possibility that VIP or PACAP have a role in the control of normal or abnormal voiding
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