Sala A, Zarini S, Bolla M
Center for Cardiopulmonary Pharmacology, University of Milan, Italy.
Biochemistry (Mosc). 1998 Jan;63(1):84-92.
The leukotrienes arise from oxidative metabolism of arachidonic acid through the action of the 5-lipoxygenase enzyme, leading to the unstable allylic epoxide leukotriene A4. This intermediate represents the substrate for two different specific enzymes, namely leukotriene A4-hydrolase and leukotriene C4-synthase, generating LTB4 and cysteinyl leukotrienes, respectively. The name "leukotriene" is referring to the cellular source (leukocytes are one of the major sources) as well as the conjugated triene that characterizes their structure. LTC4 and LTD4 are potent contracting agents of smooth muscle in airways and blood vessels; in addition, they induce mucus secretion and promote plasmatic exudation with direct action on endothelial cells. On the other side, LTB4 is known as a potent chemokinetic and chemotactic agent. A number of evidences reported in the literature underline the potential role of leukotrienes in the inflammatory responses that characterize asthma and other pathological conditions. These potent lipid bioeffectors are synthesized during the course of inflammatory reactions and their pharmacological modulation is able to significantly attenuate the clinical manifestations associated with different inflammatory pathologies.
白三烯由花生四烯酸通过5-脂氧合酶的作用进行氧化代谢产生，生成不稳定的烯丙基环氧化物白三烯A4。这种中间体是两种不同特异性酶的底物，即白三烯A4水解酶和白三烯C4合酶，分别生成LTB4和半胱氨酰白三烯。“白三烯”这个名称既指细胞来源（白细胞是主要来源之一），也指其结构中具有特征性的共轭三烯。LTC4和LTD4是气道和血管平滑肌的强效收缩剂；此外，它们可诱导黏液分泌，并通过直接作用于内皮细胞促进血浆渗出。另一方面，LTB4是一种强效的化学促动剂和趋化剂。文献中报道的大量证据强调了白三烯在以哮喘和其他病理状况为特征的炎症反应中的潜在作用。这些强效的脂质生物效应物在炎症反应过程中合成，对其进行药理调节能够显著减轻与不同炎症性疾病相关的临床表现。
