白三烯C4-d5（LTC4-d5）在19、19'，20、20和20位含有五个氘原子。它旨在用作通过GC或LC质谱法定量LTC4的内标。LTC4是母体半胱氨酰白三烯，由LTC4合酶催化谷胱甘肽与LTA4偶联产生。LTC4由嗜中性粒细胞，巨噬细胞和肥大细胞以及血小板中的跨细胞代谢产生。它是过敏反应的慢反应性物质（SRS-A）的成分之一，并具有有效的平滑肌收缩活性。LTC4诱导的支气管收缩和增强的血管通透性有助于哮喘的发病机理和急性过敏性超敏反应。产生明显的肺实质条带和孤立的气管环收缩所需的LTC4浓度约为1 Leukotriene C4-d5 (LTC4-d5) contains five deuterium atoms at the 19, 19', 20, 20 and 20 positions. It is intended for use as an internal standard for the quantification of LTC4 by GC- or LC-mass spectrometry. LTC4 is the parent cysteinyl leukotriene produced by the LTC4 synthase catalyzed conjugation of glutathione to LTA4. LTC4 is produced by neutrophils, macrophages, and mast cells, and by transcellular metabolism in platelets. It is one of the constituents of slow-reacting substance of anaphylaxis (SRS-A) and exhibits potent smooth muscle contracting activity. LTC4-induced bronchoconstriction and enhanced vascular permeability contribute to the pathogenesis of asthma and acute allergic hypersensitivity. The concentration of LTC4 required to produce marked contractions of lung parenchymal strips and isolated tracheal rings is about 1 nM.