title: Serotonin enhances urinary bladder nociceptive processing via a 5-HT3 receptor mechanism.
abstract: Serotonin from the descending pain modulatory pathway is critical to nociceptive processing. Its effects on pain modulation may either be inhibitory or facilitatory, depending on the type of pain and which receptors are involved. Little is known about the role of serotonergic systems in bladder nociceptive processing. These studies examined the effect of systemic administration of the serotonin precursor, 5-hydroxytryptophan (5-HTP), on normal bladder and somatic sensation in rats. ELISA was used to quantify peripheral and central changes in serotonin and its major metabolite following 5-HTP administration, and the potential role of the 5-HT3 receptor on changes in bladder sensation elicited by 5-HTP was investigated. 5-HTP produced bladder hypersensitivity and somatic analgesia. The pro-nociceptive effect of 5-HTP was attenuated by intrathecal, but not systemic, ondansetron. Peripheral increases in serotonin, its metabolism and rate of turnover were detectable within 30min of 5-HTP administration. Significant enhancement of serotonin metabolism was observed centrally. These findings suggest that 5-HTP increases serotonin, which may then affect descending facilitatory systems to produce bladder hypersensitivity via activation of spinal 5-HT3 receptors.
authors.affiliation: Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, 901 19th Street South, BMR2-Room 202, Birmingham, AL 35294, USA.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Hall
authors.affiliation: Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, 901 19th Street South, BMR2-Room 202, Birmingham, AL 35294, USA.
authors.forename: Cary
authors.initials: C
authors.lastname: DeWitte
authors.affiliation: Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, 901 19th Street South, BMR2-Room 202, Birmingham, AL 35294, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Ness
authors.affiliation: Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, 901 19th Street South, BMR2-Room 202, Birmingham, AL 35294, USA. Electronic address: met@uab.edu.
authors.forename: Meredith T
authors.initials: MT
authors.lastname: Robbins
mesh_terms: D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000818:Animals; D005260:Female; D059225:Nociception; D017294:Ondansetron / Q000494:pharmacology; D010147:Pain Measurement; D011917:Rats, Inbred Lew; D044406:Receptors, Serotonin, 5-HT3 / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*; D058831:Serotonin 5-HT3 Receptor Antagonists / Q000494:pharmacology; D001743:Urinary Bladder / Q000378:metabolism* / Q000503:physiopathology; D059265:Visceral Pain / Q000378:metabolism / Q000503:physiopathology
chemical_list: D044406:Receptors, Serotonin, 5-HT3; D058831:Serotonin 5-HT3 Receptor Antagonists; D012701:Serotonin; D017294:Ondansetron; D006916:5-Hydroxytryptophan
keywords: 5-Hydroxytryptophan; Hypersensitivity; Serotonin; Urinary bladder; Visceral