Department of Pharmacology, Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi, P R China.
J Pharm Pharmacol. 2009 Nov;61(11):1499-504. doi: 10.1211/jpp/61.11.0009.
The aim was to evaluate the adsorbing effect of montmorillonite on uric acid, promoting diffusion of uric acid from blood to intestine, preventing absorption of uric acid in intestine and reducing uric acid level in serum.
The adsorbing effect of montmorillonite on uric acid was observed in vitro. The intestine and blood vessel of rats were circularly perfused with intestinal perfusate and vascular perfusate, respectively. A model of hyperuricaemia in mice was prepared by intraperitoneal injection of hypoxanthine and potassium oteracil. The concentration of uric acid was determined by the method of urate oxidase and peroxide enzyme.
The results showed that different concentrations of montmorillonite could adsorb uric acid in a concentration-dependent manner. The adsorbing effect was fast. The adsorptive rate was high in acid solution and was low in alkaline solution. When blood vessels were circularly perfused by vascular perfusate containing uric acid, the concentration of uric acid in vascular perfusate was decreased and the concentration of uric acid in intestinal perfusate was increased, suggesting that uric acid in blood vessels diffused into the intestine. When the intestine was perfused with intestinal perfusate containing uric acid, the uric acid concentration in vascular perfusate was increased, but the uric acid concentration of intestinal perfusate was decreased, suggesting that uric acid was absorbed in the intestine. The uric acid concentrations of intestinal perfusate and vascular perfusate in montmorillonite 0.5 and 1.0 g/kg groups were lower than the control group. Concentrations of uric acid in serum and urine in the montmorillonite 1 and 2 g/kg groups were lower compared with mice in the hyperuricaemic group.
The results suggested that montmorillonite adsorbed uric acid and promoted diffusion of uric acid from blood vessels to intestine, prevented absorption of uric acid in intestine and decreased uric acid level in serum.
评价蒙脱石对尿酸的吸附作用，促进尿酸从血液向肠道扩散，阻止肠道对尿酸的吸收，降低血清尿酸水平。
在体外观察蒙脱石对尿酸的吸附作用。分别用肠灌流液和血管灌流液对大鼠肠和血管进行环形灌流。通过腹腔注射次黄嘌呤和氧嗪酸钾制备高尿酸血症小鼠模型。尿酸浓度采用尿酸氧化酶和过氧化物酶法测定。
结果表明，不同浓度的蒙脱石可浓度依赖性地吸附尿酸，吸附速度快。在酸性溶液中吸附率高，在碱性溶液中吸附率低。当血管用含尿酸的血管灌流液进行环形灌流时，血管灌流液中尿酸浓度降低，肠灌流液中尿酸浓度升高，提示尿酸从血管扩散到肠道。当肠用含尿酸的肠灌流液进行灌流时，血管灌流液中尿酸浓度升高，但肠灌流液中尿酸浓度降低，提示尿酸在肠道被吸收。蒙脱石 0.5 和 1.0 g/kg 组肠灌流液和血管灌流液中的尿酸浓度均低于对照组。蒙脱石 1 和 2 g/kg 组血清和尿液中的尿酸浓度均低于高尿酸血症组小鼠。
结果表明，蒙脱石吸附尿酸并促进尿酸从血管向肠道扩散，阻止肠道对尿酸的吸收，降低血清尿酸水平。
