title: The effects of reactive oxygen species on calcium- and carbachol-induced contractile responses in beta-escin permeabilized rat bladder.
abstract: The effect of reactive oxygen species on contractions in beta-escin permeabilized rat detrusor was investigated. Cumulative calcium contractions were inhibited by hydrogen peroxide (H(2)O(2)) and hydroxyl (*OH) but not by superoxide (O(2) *). The sarcoplasmic reticulum calcium-ATPase inhibitor cyclopiazonic acid (CPA) and the mitochondrial blocker carbonyl cyanide p-trifluromethoxyphenylhydrazone (FCCP) decreased the calcium contractions, however in their presence, H(2)O(2) and *OH did not have further effect. Carbachol contractions were inhibited by either H(2)O(2)/*OH/O(2) * or CPA/FCCP. In the presence of CPA, carbachol contractions were not affected by H(2)O(2) and *OH but further decreased by O(2) *. On the other hand, only H(2)O(2) and *OH elicited additional inhibition in carbachol responses in the presence of FCCP. Inositol triphosphate contraction was inhibited by *OH whereas none of the radicals affect carbachol induced calcium sensitization. These results show that H(2)O(2) and *OH affects sarcoplasmic reticulum where O(2) * acts on mitochondria to change contractions in rat detrusor smooth muscle.
authors.affiliation: Department of Pharmacology, Hacettepe University, 06100, Sihhiye, Ankara, Turkey.
authors.forename: N Tugba
authors.initials: NT
authors.lastname: Durlu-Kandilci
authors.forename: Inci
authors.initials: I
authors.lastname: Sahin-Erdemli
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000502:physiology; D002217:Carbachol / Q000494:pharmacology*; D003285:Contractile Proteins / Q000502:physiology; D004928:Escin / Q000494:pharmacology*; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000502:physiology; D008297:Male; D024101:Mitochondrial Proteins / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D010539:Permeability; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D001743:Urinary Bladder / Q000187:drug effects* / Q000502:physiology
chemical_list: D003285:Contractile Proteins; D007211:Indoles; D053496:Inositol 1,4,5-Trisphosphate Receptors; D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; D004928:Escin; D002217:Carbachol; D000252:Calcium-Transporting ATPases; D002118:Calcium; C000543:cyclopiazonic acid