ALCOHOL EFFECTS ON THE LIVER

酒精对肝脏的影响

• 批准号: 2042976
• 负责人: Jack R Wands
• 金额: $ 31.54万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-07-01 至 1998-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2042976
• 关键词: DNA replication; alcoholic beverage consumption; alcoholic fatty liver; alcoholic liver cirrhosis; alcoholism /alcohol abuse; aldehyde dehydrogenases; biopsy; cell cycle; cellular pathology; drug metabolism; enzyme mechanism; flow cytometry; gas chromatography; gel electrophoresis; gene expression; growth factor receptors; hormone regulation /control mechanism; immunoprecipitation; laboratory rat; liver function; liver regeneration; membrane activity; membrane proteins; molecular pathology; nucleic acid hybridization; nucleic acid sequence; oncogenes; phosphorylation; radionuclides; receptor binding; spectrometry; tissue /cell culture; toxicology

Our previous observations suggest that one of the major physiologic effects of alcohol on the mammalian liver is to inhibit the capacity of the liver to repair itself following a surgical deficit or cellular injury. Indeed, in vitro studies with short term hepatocyte cultures suggest that ethanol inhibits hormone stimulated DNA synthesis and that metabolism of ethanol may be required. There appears to be a critical time in the cell cycle, namely G1, where the hepatocyte may be most susceptible to the action of ethanol. We wish to consolidate and extend these gains and perform studies designed to explore the effect of ethanol at the physiologic, cellular and molecular level. We plan to do the following; 1) perform additional in vitro studies of ethanol on hormone stimulated hepatocyte DNA synthesis. In this regard, we will initiate hepatocyte cultures from animals chronically fed ethanol and determine its long term effect on the hepatocyte proliferative response. We will dispense hepatocyte cultures from rats under the influence of acute ethanol administration in the presence and absence of 4MP. Hepatocyte cultures will be prepared at various times after 2/3 hepatectomy in the setting of acute and chronic ethanol feeding. We are particularly committed to evaluate cells isolated 4 - 12 hours after surgery. 2) Pursue the effect of acute and chronic ethanol feeding on liver regeneration in vivo. We plan to assess the role of alcohol metabolism in relationship to the stage of the cell cycle. We will measure alcohol metabolism in hepatocytes at various intervals following 213 hepatectomy in concord with DNA sythesis and mitosis. Studies are planned to assess ethanol metabolism by hepatocytes in late G1 since these cells appear to be the most susceptible to the inhibitory actions of ethanol. We will use multiparameter flow cytometric analysis for determination of hepatocyte nuclear RNA and DNA content. 3) Examine the possible cellular molecular mechanisms of ethanol on hepatocyte proliferation both in vitro and in vivo. We wish to explore, therefore, ethanol effects on some of earlier events associated with hepatocyte proliferation such as oncogene activation and expression. We will evaluate rat ADH gene expression during various stages of the cell cycle and comparisons will be made to functional studies of alcohol metabolism. Finally, we will measure EGF receptor binding and subsequent autophosphorylation of its receptor and other membrane proteins. We suspect that ethanol may effect the binding and number of EGF receptors particularly prior to and during the G 0 and G 1 transition of the hepatocyte cell cycle. A clinical question to be addressed in this grant proposal. is with ongoing liver injury, the capacity of the liver to repair itself may become important and ethanol consumption may adversely effect this process. For example, continuous cellular injury in the liver that has a diminished capacity to regenerate because of ethanol exposure could promote the development of hepatic failure. Thus, a better understanding of ethanol effects on the hepatic repair process at an experimental level may have important implications with respect to the progression of clinical liver injury induced by acute and chronic alcohol abuse.

我们以前的观察结果表明，主要的生理效应之一 哺乳动物肝上的酒精是抑制肝脏的能力 在手术缺陷或细胞损伤后修复自身。的确， 短期肝细胞培养的体外研究表明乙醇 抑制激素刺激DNA合成和乙醇的代谢 可能需要。在细胞周期中似乎有一个关键的时间， 即G1，肝细胞可能最容易受到行动 乙醇。我们希望巩固和扩大这些收益并进行研究 旨在探索乙醇对生理，细胞和 分子水平。我们计划做以下内容； 1）在 乙醇对激素的体外研究刺激了肝细胞DNA合成。在 这方面，我们将长期从动物发起肝细胞培养物 喂乙醇并确定其对肝细胞的长期影响 增殖反应。我们将分配老鼠的肝细胞培养物 在存在的急性乙醇给药的影响下 缺乏4MP。肝细胞培养将在此后的不同时间准备 在急性和慢性乙醇喂养的情况下，2/3肝切除术。我们是 特别致力于评估孤立的细胞后4-12小时 外科手术。 2）追求急性和慢性乙醇对肝脏的影响 体内再生。我们计划评估酒精代谢在 与细胞周期阶段的关系。我们将测量酒精 213肝切除术后的各个间隔中的肝细胞代谢 与DNA的结论和有丝分裂的一致性。计划评估研究 G1晚期肝细胞的乙醇代谢，因为这些细胞似乎是 最容易受到乙醇抑制作用的影响。我们将使用 多参数流式细胞仪分析用于测定肝细胞 核RNA和DNA含量。 3）检查可能的细胞分子 乙醇在肝细胞增殖上的机制在体外和 体内。因此，我们希望探索乙醇对一些早期的影响 与肝细胞增殖相关的事件，例如癌基因激活 和表达。我们将在各种过程中评估大鼠ADH基因表达 细胞周期和比较的阶段将与功能研究进行 酒精代谢。最后，我们将测量EGF受体的结合和 随后其受体和其他膜蛋白的自磷酸化。 我们怀疑乙醇可能影响EGF受体的结合和数量 特别是在G 0和G 1和G 1的过渡之前 肝细胞细胞周期。这笔赠款要解决的临床问题 提议。肝脏受伤，肝脏的能力修复的能力 本身可能变得重要，乙醇的消耗可能会对 这个过程。例如，肝脏中的连续细胞损伤 由于乙醇暴露的重生能力降低的能力可能 促进肝衰竭的发展。因此，更好地理解 乙醇对实验水平上肝修复过程的影响可能 就临床进展具有重要意义 急性和慢性酒精滥用引起的肝损伤。