The physical presence of gallstone modulates ex vivo cholesterol crystallization pathways of human bile

胆石体外调节人体胆汁的胆固醇结晶途径

Background:Cholesterol crystallization is an essential step toward gallstone formation.Although model bile studies showed that competition occurs between the gallstone surface and the surrounding aqueous phase for cholesterol molecules available for crystallization,this has not been investigated in human bile.Methods:Fresh gallbladder bile was obtained during laparoscopic cholecystectomy from 13 patients with cholesterol(n紏10)or pigment(n紏3)stones.Small cholesterol gallstones were collected from another two patients.Both native and ultrafiltered bile with or without added gallstones was analysed by polarized light microscopy for the presence of arc-like and needle-like anhydrous cholesterol crystals and classic cholesterol monohydrate crystals.Weight of the added stones was evaluated before and after 21 days of bile incubation.Results:In unfiltered bile,the presence of stones was associated with a trend towards less anhydrous cholesterol crystals,but significantly more aggregated cholesterol monohydrate crystals.In ultrafiltered bile,the presence of stones tended to inhibit the formation of arc-like or needle-like crystals and was associated with significantly greater amounts of both platelike and aggregated cholesterol monohydrate crystals.After 21 days of the incubation,stone weight was decreased in both unfiltered(–4.561.6%,P紏0.046)and ultrafiltered bile(–6.561.5%,P紏0.002).Bile from pigment-stone patients was clear in the absence of stones,but showed early appearance of plate-like and aggregated cholesterol monohydrate crystals in all samples to which cholesterol gallstones were added.Conclusions:The physical presence of cholesterol gallstones in both native and filtered bile greatly influences cholesterol crystallization pathways.Whereas cholesterol monohydrate crystals increase,anhydrous cholesterol crystals tend to be inhibited.Detachment of solid cholesterol crystals from the gallstone surface may explain these findings.

背景:胆固醇结晶是胆石形成的一个必要步骤。尽管一些模拟胆汁研究显示,胆石表面与周围水相对于结晶形成过程中的胆固醇分子存在竞争关系;但相关研究尚未在人体胆汁中开展。方法:收集13例行腹腔镜胆囊切除术患者的新鲜胆汁,其中10例为胆固醇结石,3例为胆色素结石。再从其他2例患者收集小的胆固醇结石。应用偏光显微镜观察原始胆汁和超滤胆汁(加入或不加入胆石)中胆固醇结晶的形态,包括螺旋状和针状无水胆固醇结晶,以及片状和块状胆固醇单水结晶。分别于胆石加入胆汁前和加入21天后,称量胆石的重量。结果:在原始胆汁中加入胆石后,无水胆固醇结晶有减少的趋势,但块状胆固醇单水结晶显著增多。在超滤胆汁中加入胆石后,螺旋状结晶和针状结晶的形成有受抑趋势,而片状和块状胆固醇单水结晶数量显著增多。胆汁孵育21天后,胆石重量显著减轻,无论是原始胆汁(-4.5%61.6%,P=0.046)还是超滤胆汁(-6.5%61.5%,P=0.002)。来自胆色素结石患者的胆汁,在未加入胆石前是清亮的;但加入胆固醇胆石后,所有样本均早期出现片状和块状胆固醇单水结晶。结论:无论是在原始胆汁还是超滤胆汁中,加入胆固醇结石均可对胆固醇结晶途径产生重大影响,胆固醇单水结晶的数量增加,而无水胆固醇结晶的形成受抑。固态胆固醇结晶从胆石表面分离或可解释这一现象。