胆汁胆固醇对胆囊收缩素受体表达的影响

目的：探讨胆汁胆固醇对胆囊收缩素受体（CCK－R）表达的影响。方法 采用放射免疫分析法和受体放射配基结合法检测对照组、高胆固醇组、自然恢复组及治疗组豚鼠门静脉血CCK水平、胆囊CCK－R的最大结合容量（Bmax）和亲和力（Kd），同时观察空腹胆囊体积（FV）、胆囊胆汁量（FB）和餐后胆囊体积（RV）、胆囊胆汁量（RB）及胆囊收缩率（E％）、胆汁胆固醇浓度的变化。结果 与对照组比较，高胆固醇组豚鼠FV、FB增大（P＜0.05），RV、RB也增大，胆囊收缩率下降（P＜0.01），胆汁胆固醇浓度升高（P＜0.05），门静脉血CCK水平及CCK－R的Kd无改变，而CCK－R的Bmax下降（P＜0.01）；治疗组上述各项指标正常。结论 胆汁中的高胆固醇通过下调胆囊CCK－R表达而导致胆囊收缩功能障碍，降低胆汁高胆固醇浓度可以促进胆囊动力功能的恢复。

Effect of Cholesterol of Bile on the Expre ssion of Cholecystokinin Receptor

Objective: To explore the effect of cholesterol of bile on Cholecystokinin receptor (CCK R) of the gallbladder. Methods: Serum Cholecystokinin (CCK) level in portal vein, maximal binding capacity (Bmax), and Kd of CCK R in the gallbladder were measured in four groups of guniea pigs by RIA and RBA. Meanwhile the concentration of cholesterol in bile was also observed.Results:Compared with control group, after two weeks of high cholesterol feeding, there were declines in both gallbladder contraction rate( P <0.05) and Bmax of CCK R( P <0.01). In contrast, there was elevation in fasting gallbladder volume (FV) and concentration of cholesterol in bile( P <0.05) without any changes of serum CCK level and Kd of CCK R.The changes induced by high cholesterol feeding were reversed to normal levels in treated group.Conclusion:A high level of cholesterol in the gallbladder bile results in a defective muscle contraction by down regulating CCK R in the gallbladder. As a result, the reduction of cholesterol concentration of bile can result in the preservation of gallbladder contraction.