摘要
目的：研究牵拉对毒蕈碱（m）受体及5-羟色胺（5-HT）受体介导大鼠离体胃平滑肌收缩功能的影响。方法大鼠离体胃底、胃体、胃窦、贲门和幽门环行肌标本分别给予1.0，1.5，2.0，2.5和3.0 g 的前负荷，除胃窦环肌给予单浓度卡巴胆碱（ CCh）（0.3μmol·L-1）外，其余标本采用累积给药法给予 CCh 0.001~30μmol·L-1，5-HT 0.0001~30μmol·L-1，记录收缩反应。结果大鼠胃底、胃体和幽门环肌在1.0 g前负荷下，CCh 诱发收缩反应的-Log EC50值最大，-Log EC50值随前负荷升高而显著减小（P﹤0.05，P﹤0.01）；5-HT诱发胃底环行肌收缩反应结果类似。与1.0 g前负荷相比，3.0 g 前负荷时 CCh 和5-HT 诱发贲门环肌收缩反应的 Emax 值分别增大117.4%和75.7%；5-HT 诱发胃体环肌收缩反应的 Emax 值亦增大115.9%。CCh 诱发各环行肌收缩的 Emax值（g）分别为：贲门10.453±2.956（3.0 g 前负荷）、胃底13.878±2.618（2.5 g 前负荷）、胃体10.244±1.843（2.5 g 前负荷）、幽门2.585±1.098（2.5 g 前负荷）。5-HT 诱发各环肌收缩的 Emax值（g）分别为：贲门4.363±1.705（3.0 g 前负荷）、胃底3.931±0.615（3.0 g 前负荷）、胃体3.161±0.680（3.0 g 前负荷）。结论0.5 g 或1.0 g 前负荷不适于研究 m 受体和5-HT 受体介导的大鼠离体贲门、胃底、胃体和幽门环肌的收缩反应，2.0 g 前负荷可能是研究 m 受体和5-HT 受体介导大鼠离体胃环肌收缩反应的理想条件。
OBJECTlVE To investigate the effect of stretch on muscarinic receptor- and 5-hydroxytryptamine（ 5-HT）receptor-mediated contractile responses in isolated circular muscle strips taken from the rat stomach. METHODS The contractiIe responses to carbachol（CCh）0.001-30 μmol·L-1 or 5-HT 0.0001 -30 μmol·L-1 administered cumulatively were recorded in isolated circular muscIe strips taken from the gastric fundus,body,cardia and pylorus of rats under different preloads of 1.0,1.5,2.0, 2.5 and 3. 0 g,but a single concentration of CCh 0. 3 μmol·L-1 was administered to the antrum. RESULTS The -Log EC50 value for CCh in the isolated circular muscIe strips of the gastric fundus, body and pyIorus under 1.0 g preIoad was the Iargest,but decreased significantIy with higher preIoads （P﹤0.05,P﹤0.01）. A simiIar result was obtained in the isolated circular muscIe strips of the gastric body when 5-HT was used as an agonist. The Emax value of contractile responses to CCh and 5-HT in the cir-cular muscle strips of the gastric cardia under 3.0 g preIoad was increased by 117.4% and 75.7% com-pared to that under 1.0 g preIoad. The Emax value of contractile responses to 5-HT in the circular muscIe strips of the gastric body under 3.0 g preIoad was also increased by 115.9% when compared to 1.0 g preIoad. The Emax（ g） value of contractile responses to CCh in four types of muscle strips was 10.453±2.956（cardia under 3.0 g preload）,13.878±2.618（fundus under 2.5 g preIoad）,10.244±1.843 （gastric body under 2.5 g preIoad）and 2.585±1.098（pyIorus under 2.5 g preload）,respectiveIy. The Emax（g）value of contractile responses to 5-HT in three types of muscle strips was 4.363±1.705（cardia under 3.0 g preload）,3.931±0.615（fundus under 3.0 g preload）and 3.161±0.680（gastric body under 3.0 g preload）,respectiveIy. CONCLUSlON 0.5 g or 1.0 g preload is inadequate for accurate determi-nation of contractiIe responses mediated by muscarinic receptors and 5-HT receptors in isolated circular muscIe strips taken from the rat gastric cardia,fundus,body and pyIorus,but 2.0 g preIoad is optimal for investigating muscarine receptor- or 5-HT receptor-mediated contractiIe responses of isolated gastric strips of rats.
出处
《中国药理学与毒理学杂志》
CAS
CSCD
北大核心
2014年第4期519-524,共6页
Chinese Journal of Pharmacology and Toxicology
基金
国家重点基础研究发展计划(973计划)(2012 CB518601)
国家科技重大专项(2011ZX09102-011-04)~~
关键词
受体
毒蕈碱
受体
5-羟色胺
牵拉
胃体
胃底
贲门
幽门
receptors,muscarine
receptors,5-hydroxytryptamine
stretch
gastric body
fundus
cardia
pylorus
