Leukotriene D4-d5 (LTD4-d5) is intended for use as an internal standard for the quantification of LTD4 by GC- or LC-MS. LTD4 is an active metabolite of LTC4 (Item Nos. 20210 | 10007241) and a constituent of slow-reacting substance of anaphylaxis (SRS-A). It is formed via metabolism of LTC4 by γ-glutamyl transpeptidase. Like LTC4, LTD4 (0.01-0.1 pM) induces contractions in isolated guinea pig parenchymal strips and tracheal spirals. In vivo, LTD4 increases insufflation pressure, a marker of bronchoconstriction, in anesthetized guinea pigs by 100% when administered at a dose of 89 pmol per animal. It also increases vascular permeability in guinea pig skin when administered intradermally at a dose of 0.1 pmol per animal.
Leukotriene D4-d5 is the deuterium labeled Leukotriene D4. Leukotriene D4 is one of the constituents of slow-reacting substance of anaphylaxis (SRS-A) produced by the metabolism of LTC4 by γ-glutamyl transpeptidase. Leukotriene D4 is the first cysteinyl-leukotriene metabolite of LTC4. Leukotriene D4-induced bronchoconstriction and enhanced vascular permeability contribute to the pathogenesis of asthma and acute hypersensitivity.
