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The role of liver in HDL metabolism, especially proapolipoprotein A-I metabolism

肝脏在HDL代谢，尤其是载脂蛋白A-I前代谢中的作用

基本信息

批准号：
62570330
负责人：
SAKAI Hironori
金额：
$ 1.41万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62570330/
关键词：
Lipoprotein HDL Liver Apolipoprotein プロアポA-I転換酵素

项目摘要

In present study, we established the TCA assay to quantitate proapolipoprotein A-l converting activity (PAC activity) and examined serum PAC activity from patients with various liver diseases and lipoprotein disorders.Human hepatoblastoma cell line, Hep G2, were grown in near confluent monolayer culture and labeled with [<@D13@>D1H] phenylalanine for 12h. [<@D13@>D3H] labeled proapolipoprotein A-l (proapo A-l) was purified from the culturemedia by immunoaffinity purification using anti-apo A-l lgG Sepharose 4B column and then further purified by preparative SDS-polyacrylamide gel electrophoresis. Radiolabeled proapo A-l as a substrate was incubated with serum for 24h at 37゜C and then mixed for 1h at room temperature with an equal volume of 10% TCA. PAC activity was calculated from the difference between radioactivities in the TCA supernatant incubated with and without EDTA, and expressed the radioactivity/24h/ml serum.In normal control, serum PAC activity was calculated 7567 773dpm/24h … More /ml serum. Whereas in liver cirrhosis, it was significantly lower than that in normal control and was calculated 3352 1272. On the other hand, patients with hypertriglyceridemia had significantly high PAC activity at the level of 10530 3157. A significant inverse correlation was observed between PAC activity and the ratio of proapo A-l to apo A-l in serum. And serum PAC activity gave a good positive correlation with serum APO A-l and triglyceride, but no correlation were found between this activity and serum chole-sterol and HDL-cholesterol.We have demonstrated that the TCA assay should be possible to quantitate PAC activity and shown that patients with liver cirrhosis had relative low this activity and with triglyceridemia had high activity. Although the implications of the present results have not ever be made clear, it is necessary to measure PAC activity in a variety of lipoprotein disorders. And thereby we will gain insights about the function of this enzyme in the lipoprotein metabolism. Less

在本研究中，我们建立了TCA法来定量测定各种肝脏疾病和脂蛋白紊乱患者血清中a - 1转化活性（PAC活性）。人肝母细胞瘤细胞系Hep G2在近融合单层培养中生长，并用[<@D13@>D1H]苯丙氨酸标记12h。[<@D13@>D3H]标记的原载脂蛋白A-l （proapo A-l）经抗载脂蛋白A-l lgG Sepharose 4B柱免疫亲和纯化，再经制备sds -聚丙烯酰胺凝胶电泳纯化。将放射性标记的proapo a -l作为底物与血清在37℃下孵育24小时，然后在室温下与等体积的10% TCA混合1小时。PAC活性由加EDTA和不加EDTA孵育的TCA上清的放射性差计算，并表示放射性/24h/ml血清。正常对照组血清PAC活性计算为7567 773dpm/24h…More /ml血清。肝硬化组明显低于正常对照组，计算值为3352 - 1272。另一方面，高甘油三酯血症患者PAC活性显著增高，达到10530 3157水平。血清载脂蛋白A- 1与载脂蛋白A- 1比值与PAC活性呈显著负相关。血清PAC活性与血清APO a - 1、甘油三酯呈良好的正相关，与血清胆甾醇、高密度脂蛋白胆固醇无相关性。我们已经证明，TCA分析应该可以量化PAC活性，并表明肝硬化患者的PAC活性相对较低，而甘油三酯血症患者的PAC活性较高。虽然目前的结果的含义尚未明确，但有必要测量各种脂蛋白疾病中的PAC活性。因此，我们将深入了解这种酶在脂蛋白代谢中的功能。少