天麻素在大鼠小肠内吸收动力学的研究

Absorption kinetics of gastrodin in intestine of rats

目的研究天麻素在大鼠小肠内的吸收行为。方法采用大鼠在体循环方法研究天麻素在不同浓度和不同肠段下的吸收。结果在10.0~200.0 mg·L-1的质量浓度时,天麻素在小肠各段的吸收量与浓度呈线性关系,ka值基本保持不变,各肠段的吸收速率无显著性差异。在十二指肠、空肠和回肠的ka值分别为(0.143±0.044)h-1,(0.155±0.058)h-1,(0.129±0.038)h-1;与其他肠段相比,天麻素在结肠部位的吸收显著降低,ka值为(0.010±0.003)h-1。结论天麻素在肠道的吸收呈现一级动力学过程,吸收机制为被动扩散,它在小肠上中部的吸收情况较好。

Objective To study the absorption kinetics of gastrodin at different intestinal sections in rats and the influence of drug concentration on it. Method The intestines in rats were cannulated for in situ recirculation. Gastrodin concentrations in the perfusate were measured by reversed phase HPLC. Result When the concentration of gastrodin raised from 10 to 200 mg·L-1, the uptake of gastrodin increased linearly. The concentration of gastrodin had no effects on the permeability coefficient. The permeability coefficient of gastrodin at duodenum, jejunum and ileum were (0.143 ±0.044) h-1,(0.155 ±0.058) h-1 and (0.129 ±0.038) h-1, respectively. Compared with other intestinal sections in rats, the absorption of gastrodin at colon was sharply depressed with a permeability coefficient of (0.010 ±0.003) h-1. Conclusion The absorption of gastrodin in intestine of rats conformed to the first-order process under the passive diffusion mechanism. In a word, gastrodin can be ingested in the whole intestine and the absorption of it was good at the upper and middle part of the intestine while the absorption at the lower part was not as good.