Riveros-Rosas H, Julian-Sanchez A, Pinã E
Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, México, D.F.
Arch Med Res. 1997 Winter;28(4):453-71.
Ethanol or ethyl alcohol is a molecule that, in mammals, is naturally present at low concentrations due to its production by gastrointestinal flora fermentation activity. However, it is remarkable that this metabolite, with a clearly minor role in regular vertebrate metabolism, can be oxidized into acetaldehyde through several enzymatic and non-enzymatic mechanisms, which comprise the activity of more than ten enzymes and isozymes, many of them broadly distributed in different species and tissues. In correspondence, acetaldehyde can also be oxidized into acetate through several enzymatic pathways that involve about ten enzymes and isozymes which also have a broad distribution. In this article, a complete review of the aforementioned metabolic pathways is elaborated. From this group, the participation and wide distribution of alcohol dehydrogenase and aldehyde dehydrogenase systems are emphasized. The mechanisms of reaction, kinetic characteristics and physiological relevance are described, and finally, the possible physiological role of these enzymatic systems as responsible to synthesize or catabolize several endogenous metabolites that regulate growth, metabolism, differentiation and neuroendocrine function in mammals are discussed.
乙醇或酒精是一种分子，在哺乳动物中，由于胃肠道菌群的发酵活动会产生乙醇，所以其会以低浓度自然存在。然而，值得注意的是，这种在正常脊椎动物新陈代谢中作用明显较小的代谢产物，可通过多种酶促和非酶促机制氧化成乙醛，这些机制涉及十多种酶和同工酶的活性，其中许多在不同物种和组织中广泛分布。相应地，乙醛也可通过多种涉及约十种同样广泛分布的酶和同工酶的酶促途径氧化成乙酸。在本文中，对上述代谢途径进行了全面综述。在这一组中，着重强调了乙醇脱氢酶和乙醛脱氢酶系统的参与及广泛分布。描述了反应机制、动力学特征和生理相关性，最后，讨论了这些酶系统作为合成或分解代谢几种调节哺乳动物生长、代谢、分化和神经内分泌功能的内源性代谢产物的可能生理作用。
