Relaxant effects of potassium-channel openers on normal and hyper-reflexic detrusor muscle
Relaxant effects of potassium-channel openers on normal and hyper-reflexic detrusor muscle
复制标题
钾通道开放剂对正常和高反射逼尿肌的松弛作用
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
C. Chapple
中科院分区：
文献类型：
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作者：
S. W. Martin;S. Radley;R. Chess;C. Korstanje;C. Chapple
客观化
比较钾通道开放剂左克罗卡林和YM934对正常和反射亢进膀胱的人逼尿肌的作用。
材料和方法
用氨基甲胆碱预收缩正常和高反射膀胱的人逼尿肌 条，并在器官浴中累积加入钾通道开放剂(0.1~0.3molμ/L)。其他条带的场激频率分别为场激最大反应的25%和75%。阿托品(10μ摩尔/L)和河豚毒素(1μ摩尔/L)可解除收缩。
结果
反射亢进的膀胱 对氨基甲胆碱的敏感性显着高于正常膀胱，但反射亢进组织的最大反应显着低于正常膀胱。在正常和反射亢进的逼尿肌中，钾通道开放剂的效力没有显著差异。反射亢进的膀胱对电场刺激的敏感性显著高于正常膀胱；对电场刺激的最大反应没有显著差异。在高反射性膀胱中，钾通道开放剂的浓度-反应曲线在25%和75%的最大频率下都向左移动；然而，只有左克罗卡林在最大频率的75%时才有显著的移位。
结论
，反射亢进的膀胱对氨基甲胆碱和磁场刺激的敏感性更高，这支持了现有证据表明，逼尿肌不稳定中存在连接后超敏感。本研究结果还提示，不稳定膀胱的KATP通道功能无明显变化。
Objective
To compare the effects of the potassium-channel openers, levcromakalim and YM934, in isolated human detrusor muscle from normal and hyper-reflexic bladders.
Materials and methods
Strips of human detrusor muscle from normal and hyper-reflexic bladder were pre-contracted with carbachol and the potassium-channel openers (0.1–0.3 μmol/L) were added cumulatively to the organ baths. Other strips were field-stimulated at frequencies producing 25% and 75% of the maximum response to field stimulation. Contractions could be abolished by atropine (10 μmol/L) and tetrodotoxin (1 μmol/L).
Results
The hyper-reflexic bladder was significantly more sensitive to carbachol than the normal bladder but the maximum response was significantly lower in the hyper-reflexic tissue. There was no significant difference between the potency of the potassium-channel openers in normal and hyper-reflexic detrusor muscle. Hyper-reflexic bladder was significantly more sensitive to electrical field stimulation than was normal bladder; maximum responses to field stimulation were not significantly different. Concentration-response curves for the potassium-channel openers were displaced to the left in hyper-reflexic bladder at both 25% and 75% maximum frequencies; however, only with levcromakalim at 75% of the maximum frequency was the shift significant.
Conclusion
The greater sensitivity of hyper-reflexic bladder to carbachol and field stimulation supports existing evidence for post-junctional supersensitivity in detrusor instability. The results of this study also suggest that there are no appreciable changes in KATP channel function in the unstable bladder.