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STUDY OF BILE ACID BIOSYNTHESIS OF FETAL BILE ACIDS AND CONGENITAL DISORDERS

胎儿胆汁酸的胆汁酸生物合成与先天性疾病的研究

基本信息

批准号：
09672197
负责人：
KUROSAWA Takao
金额：
$ 1.98万
依托单位：
HEALTH SCIENCES UNIVERSITY OF HOKKAIDO
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09672197/
关键词：
fetal bile acid bile acid biosynthesis disorder C27-bile acid biosynthesis intermediates HPLC GC MS enzymatic specificitiy stereospecificity

项目摘要

Biosynthetic pathway of bile acids in the neonatal petiod is of interest in connection with the development of neonatal liver function. However, the above pathway has not been clearly established.Recently, the fetal bile acids have been found and their expected intermediateshave also been identified in the biological fluids of patients with congenital bile acid disorder. From the above point of view, the following subjects have been studied in this project.1)Synthesis of bile acid intermediates in neonatal period. 2)Establishment of quantitative analysis for bile acid intermediates. 3)Olarification of the role and function of enzymes in bile acid biosynthesis andquantitative analysis of bile acid component in congenital disorder.The biosynthetic intermediates (1beta and Gci-hydroxylated cholestan-26-oic acids) and their analogues with deifrent hydroxyl group numbers and side chain structures were synthesized by the modification of previously reported method as the authentic specimens for establishment of analysis and as substrates for enzymatic study. Usingthe above compounds, the quantitative analytical methods were establised by the use of HPLC, GO and GO/MS.The above methods were then applied for the determination of metabolites of enzymatic reaction (hydratase/dehydrogenase, thiolase in side chain degradation step). The results indicated that the enzymatic reaction (hydratase/dehydrogenase) proceed substrate and stereospecifically to give 24-hydroxylated cholestanoic acid with 24R,25R-stereochemistry. It was also indicated that steroid carieer protein 2 shows the thiolase actvities. The analysis of bile acids in urine and serum of patients with liver disease showed the significant accumulation of abnormal bile acids (3-oxo-DELTA4-bile acids) indicating enzymatic disorder (probably disorder of 3-oxo-DELTA4-steroid reductase) of bile acid biosynthesis of the above patients, .

新生儿时期胆汁酸的生物合成途径与新生儿肝功能的发展有关。然而，上述途径尚未明确确立。最近，在先天性胆汁酸紊乱患者的生物体液中发现了胎儿胆汁酸及其预期的中间体。综上所述，本项目主要研究了以下几个课题。1)新生儿期胆汁酸中间体的合成。2)建立胆汁酸中间体定量分析方法。3)先天性疾病中胆汁酸生物合成酶的作用和功能及胆汁酸成分的定量分析。通过对已有报道方法的修改，合成了具有不同羟基数和侧链结构的1 - β和gci羟基化胆甾醇-26-酸及其类似物，作为建立分析的真实样本和酶促研究的底物。采用高效液相色谱（HPLC）、氧化石墨烯（GO）和氧化石墨烯/质谱（GO/MS）建立了上述化合物的定量分析方法。然后将上述方法应用于酶促反应（水合酶/脱氢酶、侧链降解步骤中的硫硫酶）代谢产物的测定。结果表明，酶促反应（水合酶/脱氢酶）进行底物和立体特异性反应，得到具有24R、25r立体化学性质的24-羟基化胆甾酸。结果表明，甾体蛋白2具有巯基酶活性。肝病患者尿液和血清胆汁酸分析显示，异常胆汁酸（3-氧- delta4 -胆汁酸）明显积聚，提示上述患者胆汁酸生物合成酶功能紊乱（可能是3-氧- delta4 -类固醇还原酶功能紊乱）。