[Effect of montmorillonite on diffussion of urea between blood and intestine and on absorption of intestine in rats].

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 administrated 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.