不同钙浓度对胆汁酸结合能力影响

Effect of calcium concentration on combining capacity of bile acid in vitro

目的探讨不同钙浓度对胆汁酸结合能力的影响。方法配制不同浓度的磷酸氢钙溶液,调整pH至7.0,加入胆汁酸混合乳糜微粒,在37℃条件下进行体外消化实验。测定不同浓度钙消化液的上清液和沉淀物中胆汁酸的含量。结果胆汁酸在5,10,20,40,80mmol/L钙消化液的上清液中的含量分别为（2.72±0.27）,（1.48±0.07）,（0.64±0.04）,（0.63±0.07）,（0.76±0.09）μmol;在沉淀物中的含量分别为（1.45±0.09）,（2.56±0.18）,（3.36±0.19）,（3.21±0.28）,（3.24±0.25）μmol。其中5和10mmol/L钙消化液的上清液和沉淀物中的胆汁酸含量与其他浓度消化液比较,差异有统计学意义（P〈0.05）。不同浓度钙消化液的胆汁酸回收率范围在95.98%-112.82%之间。40mmol/L钙浓度组的胆汁酸回收率显著低于5,10,20mmol/L钙浓度组（P〈0.05）。结论钙在模拟人体小肠的pH和温度条件下可与磷形成沉淀物而结合胆汁酸,且钙浓度为20mmol/L时结合胆汁酸的能力最强。

Objective To investigate the effect of different cocentrations of calcium on the combining capacity of bile acid. Methods Different concentrations of calcium hydrogen phosphate solution were prepared and adjusted to pH = 7.0. Then bile acid mixture chytomicron was added to the solutions digested at 37℃ in vitro. The contents of bile acid were meastared in the supematant and the sediment of different concentrations of calcium solution. Results Bile acid content was（2.72 ±0.27）, （1.48 ± 0.07）, （0.64 ± 0.04）, （0.63 ± 0.07）, （0.76 ± 0.09） μmol in supematant and （1.45 ± 0.09）, （2.56 ± 0.18）, （3.36 ± 0.19）, （3.21 ± 0.28）, （3.24 ±0.25）μmol in sediment of the 5, 10, 20, 40, 80mmol/L digested calcium solution, respectively. Compared with other concentrations of calcium solution, bile acid contents in the supernatant and the sedi- ment of the 5 and 10mmol/L digested calcium solution were different statistically（P 〈 0.05）. The bile acid recoveries of digested solution from different calcium concetration were 95.98 % -112.82 %. The bile acid recovery of 40mmol/L calcium solution was lower than that of 5, 10, 20mmol/L calcium solution statistically （ P 〈 0.05 ）. Conclusion Calcium with phosphorus forms sediment can combine with bile acid at the pH and the temperature similar to that of in human small intestine, and the combining capacity is the highest at calcium concentration of 20mmol/L.