荷叶碱大鼠肠道吸收特性研究

 目的 用肠管外翻模型研究荷叶碱在大鼠不同肠段的体外肠吸收特征。方法 在不同肠段(十二指肠、空肠、回肠和结肠)的肠管外翻模型中分别加入10、20和40 μg·mL-1的荷叶碱，在不同时间点取样，采用Agilent 1100型高效液相色谱仪测定肠囊内药物浓度，计算荷叶碱的吸收参数来分析其在肠道的吸收特征，比较不同肠段对荷叶碱通透能力的差异。结果 37 ℃下，不同浓度的荷叶碱在台氏液中2.5 h内稳定，方法学考察均符合生物样品的测定要求。荷叶碱在大鼠不同肠段中的吸收在一定浓度内无饱和现象，十二指肠、空肠、回肠和结肠的吸收速率常数依次为（0.014 4±0.005 4）、（0.019 6±0.003 3）、（0.021 5±0.004 4）、（0.017 8±0.003 2） min-1。结论 荷叶碱在大鼠不同肠段的转运为一被动扩散过程，不同肠段的吸收具有线性吸收的特征，吸收速度依次如下：回肠、空肠、结肠和十二指肠。

Study on Absorption Profiles of Nuciferine in Rat Intestine

OBJECTIVE To study the absorption profiles of nuciferine in different intestinal sections, ie duodenum, jejunum, ileum and colon. METHODS Sac containing drug free Tyrode solution was immersed in Tyrode solution containing 10, 20 and 40 μg·mL-1 nuciferine. The solution inside the sac was collected, and the drug concentration was determined by HPLC method. Absorption parameter of nuciferine in different part of rat intestine was obtained to evaluate its profiles. RESULTS Nuciferine of different concentrations was stable in tyrode solution in 37 ℃ within 2.5 h. The developed method was validated for the determination of nuciferine in tyrode solution. The absorption of nuciferine in different intestinal sections was not saturated within a certain range of concentration, and the absorption rate constants in duodenum, jejunum, ileum and colon were （0.014 4±0.005 4）, （0.019 6±0.003 3）, （0.021 5±0.004 4） and （0.017 8±0.003 2） min-1， respectively. CONCLUSION The absorption of nuciferine was linear in different parts of intestine at different dosages. The order of the absorption rate was ileum> jejunum> colon> duodenum.