Durlu-Kandilci N Tugba, Sahin-Erdemli Inci
Department of Pharmacology, Hacettepe University, 06100, Sihhiye, Ankara, Turkey.
Naunyn Schmiedebergs Arch Pharmacol. 2008 Dec;378(6):645-53. doi: 10.1007/s00210-008-0326-3. Epub 2008 Jul 19.
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.
研究了活性氧对β-七叶皂苷通透的大鼠逼尿肌收缩的影响。过氧化氢（H₂O₂）和羟基自由基（OH）可抑制累积钙收缩，但超氧阴离子（O₂）则无此作用。肌浆网钙ATP酶抑制剂环匹阿尼酸（CPA）和线粒体阻滞剂羰基氰化物对三氟甲氧基苯腙（FCCP）可降低钙收缩，然而在它们存在的情况下，H₂O₂和OH并无进一步影响。卡巴胆碱收缩可被H₂O₂/OH/O₂或CPA/FCCP抑制。在CPA存在的情况下，卡巴胆碱收缩不受H₂O₂和OH影响，但可被O₂进一步降低。另一方面，在FCCP存在的情况下，只有H₂O₂和OH对卡巴胆碱反应产生额外抑制。肌醇三磷酸收缩可被OH抑制，而这些自由基均不影响卡巴胆碱诱导的钙敏化。这些结果表明，H₂O₂和OH作用于肌浆网，而O₂*作用于线粒体，从而改变大鼠逼尿肌平滑肌的收缩。
