近足月妊娠母羊的肝脏、胎儿肝脏及胎盘组织中乙醇脱氢酶和乙醛脱氢酶的活性

Activity of alcohol dehydrogenase and aldehyde dehydrogenase in maternal liver, fetal liver and placenta of the near-term pregnant ewe.

作者信息

Clarke D W, Smith G N, Patrick J, Richardson B, Brien J F

机构信息

Department of Pharmacology and Toxicology, Faculty of Medicine, Queen's University, Kingston, Ont.

出版信息

Dev Pharmacol Ther. 1989;12(1):35-41.

PMID:2721331

Abstract

The activity of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) was determined in the near-term pregnant ewe. There was little ADH activity in fetal liver (4.4%) and placenta (0.2%) compared with maternal liver. Low KM (microM acetaldehyde) ALDH activity was similar in the three tissues. High KM (mM acetaldehyde) ALDH activity was less in fetal liver (57%) and placenta (16%) compared with maternal liver. These data and the pharmacokinetics of ethanol and its proximate metabolite, acetaldehyde, in the near-term pregnant ewe indicate that ethanol elimination from the maternal-fetal unit is regulated primarily by maternal hepatic ADH-catalyzed biotransformation of ethanol, and low KM ALDH activity in the fetal liver and placenta protects the fetus from exposure to ethanol-derived acetaldehyde, which is produced primarily in the maternal compartment.

摘要

在接近足月妊娠的母羊中测定了乙醇脱氢酶（ADH）和乙醛脱氢酶（ALDH）的活性。与母羊肝脏相比，胎儿肝脏（4.4%）和胎盘（0.2%）中的ADH活性很低。低Km（微摩尔乙醛）的ALDH活性在这三种组织中相似。与母羊肝脏相比，胎儿肝脏（57%）和胎盘（16%）中的高Km（毫摩尔乙醛）的ALDH活性较低。这些数据以及接近足月妊娠母羊中乙醇及其直接代谢产物乙醛的药代动力学表明，乙醇从母胎单位的消除主要受母羊肝脏中ADH催化的乙醇生物转化调节，胎儿肝脏和胎盘中低Km的ALDH活性可保护胎儿免受主要在母体部分产生的乙醇衍生乙醛的暴露。