Cheung Connie, Davies Non G, Hoog Jan-Olov, Hotchkiss Sharon A M, Smith Pease Camilla K
Department of Molecular Toxicology, Section of Biological Chemistry, Division of Biomedical Sciences, Sir Alexander Fleming Building, Imperial College School of Medicine, South Kensington, London, UK.
Toxicology. 2003 Mar 3;184(2-3):97-112. doi: 10.1016/s0300-483x(02)00552-8.
Alcohol dehydrogenase (ADH; EC. 1.1.1.1) and aldehyde dehydrogenase (ALDH; EC 1.2.1.3) play important roles in the metabolism of both endogenous and exogenous alcohols and aldehydes. The expression and localisation patterns of ADH (1-3) and ALDH (1-3) were investigated in the skin and liver of the mouse (BALB/c and CBA/ca), rat (F344) and guinea-pig (Dunkin-Hartley), using Western blot analysis and immunohistochemistry with class-specific antisera. ALDH2 expression and localisation was also determined in human skin, while ethanol oxidation, catalysed by ADH, was investigated in the mouse, guinea-pig and human skin cytosol. Western blot analysis revealed that ADH1, ADH3, ALDH1 and ALDH2 were expressed, constitutively, in the skin and liver of the mouse, rat and guinea-pig. ADH2 was not detected in the skin of any rodent species/strain, but was present in all rodent livers. ALDH3 was expressed, constitutively, in the skin of both strains of mouse and rat, but was not detected in guinea-pig skin and was absent in all livers. Immunohistochemistry showed similar patterns of expression for ADH and ALDH in both strains of mouse, rat, guinea-pig and human skin sections, with localisation predominantly in the epidermis, sebaceous glands and hair follicles. ADH activity (apparent V(max), nmoles/mg protein/min) was higher in liver (6.02-16.67) compared to skin (0.32-1.21) and lower in human skin (0.32-0.41) compared to mouse skin (1.07-1.21). The ADH inhibitor 4-methyl pyrazole (4-MP) reduced ethanol oxidation in the skin and liver in a concentration dependent manner: activity was reduced to approximately 30-40% and approximately 2-10% of the control activity, in the skin and liver, respectively, using 1 mM 4-MP. The class-specific expression of ADH and ALDH enzymes, in the skin and liver and their variation between species, may have toxicological significance, with respect to the metabolism of endogenous and xenobiotic alcohols and aldehydes.
乙醇脱氢酶（ADH；EC. 1.1.1.1）和乙醛脱氢酶（ALDH；EC 1.2.1.3）在内外源性醇类和醛类的代谢中发挥着重要作用。利用蛋白质免疫印迹分析以及使用种属特异性抗血清进行免疫组织化学方法，对小鼠（BALB/c和CBA/ca）、大鼠（F344）和豚鼠（Dunkin-Hartley）的皮肤和肝脏中ADH（1 - 3）和ALDH（1 - 3）的表达及定位模式进行了研究。同时也测定了人皮肤中ALDH2的表达及定位，并且对小鼠、豚鼠和人皮肤胞质溶胶中由ADH催化的乙醇氧化进行了研究。蛋白质免疫印迹分析显示，ADH1、ADH3、ALDH1和ALDH2在小鼠、大鼠和豚鼠的皮肤和肝脏中组成性表达。在任何啮齿动物物种/品系的皮肤中均未检测到ADH2，但在所有啮齿动物的肝脏中均有表达。ALDH3在两种品系的小鼠和大鼠皮肤中组成性表达，但在豚鼠皮肤中未检测到，且在所有肝脏中均不存在。免疫组织化学显示，在小鼠、大鼠、豚鼠和人皮肤切片中，ADH和ALDH的表达模式相似，主要定位于表皮、皮脂腺和毛囊。肝脏中的ADH活性（表观V(max)，纳摩尔/毫克蛋白质/分钟）（6.02 - 16.67）高于皮肤（0.32 - 1.21），而人皮肤中的ADH活性（0.32 - 0.41）低于小鼠皮肤（1.07 - 1.21）。ADH抑制剂4 - 甲基吡唑（4 - MP）以浓度依赖性方式降低皮肤和肝脏中的乙醇氧化：使用1 mM 4 - MP时，皮肤和肝脏中的活性分别降至对照活性的约30 - 40%和约2 - 10%。ADH和ALDH酶在皮肤和肝脏中的种属特异性表达及其在不同物种间的差异，对于内源性和外源性醇类及醛类的代谢可能具有毒理学意义。
