蒙脱石对尿素在大鼠血管和肠道间的扩散及肠道吸收的影响

Effect of Montmorillonite on Diffussion of Urea between Blood and Intestine and on Absorption of Intestine in Rats

目的:研究蒙脱石对血管循环灌流液中的尿素向肠道扩散的促进作用和阻止肠道循环灌流液中尿素的吸收作用。方法:大鼠在体肠道、血管分别用含或不含尿素的血管灌流液和肠灌流液进行循环灌流,用脲酶、谷氨酸脱氢酶偶联法测定尿素含量。结果:血管用含尿素的血管灌流液循环灌流,肠道用不含尿素的肠道灌流液循环灌流,血管灌流液中的尿素浓度逐渐下降,而肠道灌流液中的尿素浓度逐渐升高;同时肠道中加入蒙脱石时,蒙脱石0.5 g/kg和1.0 g/kg组的血管灌流液和肠道灌流液中的尿素浓度均明显低于对照组(P<0.05)。血管用不含尿素的血管灌流液循环灌流,肠道用含尿素的肠道灌流液循环灌流,肠道灌流液中的尿素浓度逐渐下降,而血管灌流液中的尿素浓度逐渐升高;同时肠道中加入蒙脱石时,蒙脱石0.5 g/kg和1.0 g/kg组肠道灌流液和血管灌流液中尿素浓度明显低于阴性对照组(P<0.05)。结论:蒙脱石可以促进尿素从血管向肠道的扩散,并降低尿素在大鼠肠道的吸收。

Objective ： To study the effect of montmorillonite on promoting diffussion of urea from blood vessel to intestine and preventing absorption of urea in intestine. Methods ： Rat intestine tract and blood vessel were perfusated circularly with intestinal tract perfusate and blood vessel perfusate with or without urea 1 g/L, respectively. The concentration of urea in perfusates was measured by urease and glutamic dehydrogenase coupling method. Results ：The blood vessel was circularly perfusated with vascular perfusate containing urea and intestinal tract was circularly perfusated with intestinal perfusate without urea. The concentration of urea in vascular perfusate decreased gradually, and the concentration of urea in intestine perfusate increased slowly. When montmorillonite was added into the intestinal tract, the urea concentration in both intestinal tract perfusate and the vascular perfusate in montmorillonite 0. 5 g/kg and 1.0 g/ kg groups were significantly lower than that of control group （ P 〈 0. 05 ）. The blood vessel was circularly perfusated with vascular perfusate without urea and intestinal tract was circularly perfusated with perfusate containing urea, the concentration of urea in intestine perfusate decreased little by little, and the concentration of urea in vascular perfusate increased slowly. After montmorillonite was ad- ministrated into the intestinal tract, the urea concentrations in both the vascular perfusate and intestinal tract perfusate in montmorillonite 0. 5 g/kg and 1.0 g/kg were obviously lower than that of control group （P 〈 0. 05 ）. Conclusion ： Montmorillonite promotes the diffusion of urea from blood vessel to intestine, and inhibits the absorption of urea in intestine.