• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>American Journal of Physiology >Desensitization of the peristaltic reflex induced by mucosal stimulation with the selective 5-HT4 agonist tegaserod.
【24h】

Desensitization of the peristaltic reflex induced by mucosal stimulation with the selective 5-HT4 agonist tegaserod.

机译：选择性5-HT 4激动剂替加色罗通过粘膜刺激引起的蠕动反射脱敏。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The intestinal peristaltic reflex induced by mucosal stimulation is mediated by mucosal release of serotonin (5-HT), which acts on 5-HT(4) receptors located on CGRP-containing afferent nerve terminals. Exposure of the colonic mucosa to the 5-HT(4) receptor agonist tegaserod in the range of 1 nM to 10 muM elicits a peristaltic reflex and stimulates colonic propulsion. The present study was designed to identify the 5-HT(4) receptor subtype mediating the reflex and determine whether functionally effective concentrations of tegaserod desensitize the reflex induced by mucosal stimulation. Exposure of rat colonic mucosa to tegaserod in the range of 5 nM to 5 muM for 5 or 10 min caused rapid time- and concentration-dependent desensitization of the peristaltic reflex induced by mucosal stroking, consistent with the operation of a rapidly desensitizing 5-HT(4b) receptor subtype. Desensitization was accompanied by a decrease in CGRP release. The rate of recovery of peristaltic response depended on the desensitizing concentration of tegaserod: ascending contraction and descending relaxation recovered within 15 min after 5-50 nM tegaserod, 30 min after 0.5 muM, and 60 min after 5 muM. Neither CGRP release nor the peristaltic reflex induced by muscle stretch was affected by 5-HT(4) receptor desensitization, providing further evidence that 5-HT does not mediate the reflex induced by muscle stretch. These results suggest in cases of increased 5-HT availability or prolonged exposure, such as colitis, that it is likely the peristaltic reflex will be blunted.
机译：黏膜刺激诱导的肠蠕动反射是由5-羟色胺（5-HT）的黏膜释放介导的，5-HT作用于位于含有CGRP的传入神经末梢的5-HT（4）受体。结肠粘膜暴露于1nM至10μM范围内的5-HT（4）受体激动剂替加色罗会引起蠕动反射并刺激结肠推进。本研究旨在确定介导反射的5-HT（4）受体亚型，并确定功能有效浓度的替加色罗是否对由粘膜刺激引起的反射脱敏。大鼠结肠粘膜暴露在5 nM至5μM的替加色罗中5或10分钟导致粘膜抚摸引起的蠕动反射的时间依赖性和浓度依赖性快速脱敏，这与快速脱敏的5-HT的操作相一致（4b）受体亚型。脱敏伴随着CGRP释放的减少。蠕动反应的恢复速率取决于替加色罗的脱敏浓度：在5-50 nM替加色罗后15分钟内，0.5μM后30分钟和5μM后60分钟内恢复了上升收缩和下降松弛。 CGRP释放或由肌肉拉伸引起的蠕动反射都不受5-HT（4）受体脱敏的影响，进一步提供了证据表明5-HT不会介导由肌肉拉伸引起的反射。这些结果表明，在5-HT利用率增加或暴露时间延长（例如结肠炎）的情况下，蠕动反射可能会变钝。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号