成石前后胆囊粘膜上皮多聚核蛋白体RNA含量变化—胆液糖蛋白和蛋白质增加的机制探讨

Changes of Polyribosme RNA Content at the Gallbladder Epithe- lium in Sludge and Gallstones——Mechanisms of Increased Biliary Mucus Glycoprotein and Proteins

胆囊淤泥是胆囊结石的前身。测定胆囊粘膜上皮游离(FPR)和结合多聚核蛋白体(MBPR)的RNA含量及胆液粘液糖蛋白(MGP)的结果表明:胆囊淤泥患者胆囊粘膜合成和分泌MGP明显亢进,MBPR与相应GB中MGP的相关性比较提示此时尚有胆液淤积存在,且FPR的RNA含量也显著增高,提示细胞增殖加快。荧光胺法测定胆液蛋白质的含量发现,胆囊淤泥和胆固醇性结石患者胆囊液GB蛋白质含量显著高于色素性结石患者及“正常”对照,但蛋白质的GB浓度与HB浓度的比值显著低于胆固醇GB/HB比值,且GB中MGP与蛋白质含量呈显著正相关。说明蛋白质含量的增加与GB中过高的MGP阻止胆囊中蛋白质的清除过程有关。成石前GB中MGP和蛋白质含量的同时增高及其机制的确立,对认识及预防体内结石均有意义。

Biliary sludge has been observed as a precursor to gallstone development. The gallbladder bile(GB)mucus glycoprotein (MGP) and the RNA content of the membrane-bound polyribosome(MBPR) at gallbladder epithelium were significantly higher in patients of the sludge group than those of the cholesterol and pigment gallstones and control group. These facts demonstrated that the increased synthesis and secretion of glycoprotcins exist?d in the pre-stone stage of gallstones. The RNA content of MBPR in epithelial cells should correlate with the MGP concentrations in GB in theory, however, this was true only in three groups except the sludge group, which suggest there was other reason for that highest mucus content besides the increase in MGP synthesis and secretion. It would be reasonable to assume that it was due to the stasis of gallbladder. The RNA content of free polyribosome in the sludge was also significantly greater than in controls, so in that stage of gallstones the increase in cell proliferation had been taken place in the gallbladder epithelium. Persons with sludge and cholesterol gallstone had significantly higher protein concentrations in GB than patients without gallstones or with pigment stones. The gallbladder-hepatic bile ratio of proteins was significantly less than that of cholesterol gallstones group, and there was a highly significant correlation between the glycoproteins and proteins in GB. Therefore, the only reasonable explanation for the higher protein content in these two kinds of patients was probably that the high concentrations of MGP prevented the clearance of biliary proteins in the gallbladder. The increases of MGP and proteins concentrations in GB in the embryonic stage of gallstones were the evidence that they may be recognized as nucleation factors in vivo, and the understanding of the mechanisms of increased MGP and proteins might have a potential value in prevention of gallstone formation.