摘要
目的:探讨中药单体环维黄杨星D(CVB-D)对大鼠在体回肠的作用及其机制.方法:经十二指肠插管给予不同浓度的CVB-D,观察CVB-D对回肠收缩的影响,并分离培养大鼠回肠平滑肌细胞,应用钙敏感的荧光指示剂Fura-2,于荧光分光光度计上测定平滑肌细胞内游离钙离子浓度([Ca2+]i).结果:给药组在给予CVB-D110min以后大鼠回肠的收缩幅度增强,而预先给予钙通道阻滞药硝苯地平可拮抗其对回肠的收缩作用.当回肠平滑肌细胞悬液细胞外钙([Ca2+]o)为1.5mmol/L时,CVB-D可诱发静息期[Ca2+]i升高,而预先给予维拉帕米可以抑制[Ca2+]i的升高,抑制率为17.9%;当[Ca2+]o为零时,CVB-D仍可使[Ca2+]i升高,而普鲁卡因对[Ca2+]i升高的抑制率达29.2%.结论:大鼠回肠平滑肌受CVB-D刺激后,回肠的收缩幅度明显增加,作用机制可能与增加肠平滑肌细胞[Ca2+]i有关,而[Ca2+]i增加主要来源于细胞外Ca2+经电压依赖性钙离子通道内流及肌浆网雷诺定(ryanodine)敏感的贮存Ca2+释放.
AIM： To explore the effects of cyclovirobuxine D （CVB-D） on rat ileum in vivo and its mechanisms. METHODS ： Various concentration of CVB-D were intraduodenally given to observe the effects of CVB-D on the contractive amplitude of ileum. Then rats ileal myoeytes were isolated and cultured. The calcium concentration in isolated ileal myoeytes was determined by using calcium sensitive fluorescence indicator Fura-2 technique. RESULTS： After 110 rain, the contractive amplitude of rats ileum in administration groups increased. But under pretreatment with calcium channel blocker, nifedipine, the above effects were antagonized. Resting [ Ca^2＋ ]i in ileal myoeytes under 1. 5 mmol/L of extracellular calcium concentration was concentrationdependently increased by CVB-D. Verapamil inhibited the [ Ca^2＋ ]i elevation induced by CVB-D and the inhibition rate was 17.9%. Under 0 mmol/L of extracellular calcium concentration, CVB-D also induced [ Ca^2＋]i to increase and the inhibition rate of heparin was 29.2%. CONCLUSION： CVB-D can strengthen contractive amplitude of rats ileum in vivo, and the mechanisms may be related to [ Ca^2＋]i increasing of ileal myocytes, which is mainly due to influx of extracellular calcium by voltage-dependent calcium channel and mobilization of ryanodine-sensitive intracellular stored calcium.
出处
《第四军医大学学报》
北大核心
2007年第23期2156-2159,共4页
Journal of the Fourth Military Medical University
基金
广西教育厅科研项目(200501066)
