Serotonergic modulation of cat bladder function before and after spinal transection.
Micturition was evoked in conscious cats by infusing saline into the bladder at a physiological rate. Drugs were administered intrathecally. Micturition volume threshold was increased by 5-hydroxytryptamine (5-HT, serotonin) and decreased by zatosetron, a 5-HT3 receptor antagonist, in spinally intact cats. Thus 5-HT3 receptors inhibit micturition. After complete spinal transection, serotonin reduced volume threshold in 3 of 4 cats, indicating an alteration in serotonergic control. However, 2-methyl-5-HT, a 5-HT3 receptor agonist, increased volume threshold. Thus 5-HT3 receptor-mediated inhibition of bladder function remains after spinal transection. We conclude that some, but not all, serotonergic modulation of bladder function is altered after spinal transection.
Espey
M J
MJ
Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada.
Downie
J W
JW
D000818:Animals; D001572:Benzofurans / Q000494:pharmacology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002415:Cats; D004305:Dose-Response Relationship, Drug; D008297:Male; D012701:Serotonin / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects / Q000503:physiopathology; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D013997:Time Factors; D001743:Urinary Bladder / Q000187:drug effects* / Q000503:physiopathology; D014554:Urination / Q000187:drug effects* / Q000502:physiology
D001572:Benzofurans; D019086:Bridged Bicyclo Compounds, Heterocyclic; D012701:Serotonin; C064877:zatosetron