leukotriene c-4

Leukotriene C4 (LTC4) 是一种类花生酸脂质介质，可调节炎症部位白细胞的募集和功能。Leukotriene C4 是支气管收缩、粘液分泌过多和嗜酸性粒细胞增多的介质，在荨麻疹中具有介导作用。

Sulfasalazine (Azulfidine) 是一种合成的水杨酸衍生物，对含有弹性蛋白的结缔组织具有亲和力，并配制成前药。Sulfasalazine 可以诱导铁死亡，抑制 NF-κB、TGF-β 和 COX-2。

11-trans Leukotriene C4 (11-trans LTC4) is a C-11 double bond isomer of LTC4. LTC4 undergoes slow temperature-dependent isomerization to 11-trans LTC4 during storage. 11-trans LTC4 is produced in smaller amounts relative to LTC4 in ionophore-stimulated HMC-1 cells (a human mast cell line) and equine eosinophils, but not in human neutrophils or RBL-1 cells. It is nearly equipotent with LTC4 for contraction of guinea pig parenchymal and ileum. In a radioligand binding assay using guinea pig ileum as a cysteinyl leukotriene receptor preparation, the pKis for LTC4 and 11-trans LTC4 were determined to be 6.42 and 6.58, respectively.

Leukotriene C4 (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. LTC4 methyl ester is a more lipid soluble form of LTC4. The biological activity of LTC4 methyl ester has not been reported.

Produced by neutrophils, macrophages, mast cells, and by transcellular metabolism in platelets, leukotriene C4 (LTC4) is the parent cysteinyl leukotriene formed by the LTC4 synthase-catalyzed conjugation of glutathione to LTA4. It is one of the constituents of slow-reacting substance of anaphylaxis (SRS-A) and exhibits potent smooth muscle contracting activity. LTC4, however, is rapidly metabolized to LTD4 and LTE4, which makes the characterization of LTC4 pharmacology difficult. N-methyl Leukotriene C4 (N-methyl LTC4) is a synthetic analog of LTC4 that is not readily metabolized to LTD4 and LTE4.It acts as a potent and selective CysLT2 receptor agonist exhibiting EC50 values of 122 and > 2,000 nM at the human CysLT2 and CysLT1 receptors, respectively. It has essentially the same potency as LTC4 at both the human and murine receptors CysLT2 receptors. N-methyl LTC4 is potent and active in vivo, causing vascular leak in mice overexpressing the human CysLT2 receptor but not in CysLT2 receptor knockout mice.

Leukotriene C4 (14,15-LTC4) is an inflammatory mediator synthesized from arachidonic acid through the actions of 15- and 12-lipoxygenases (LOs), involving intermediates such as 15-HpETE and 14,15-LTA4. Unlike the majority of leukotrienes formed via the 5-LO pathway, 14,15-LTC4 is an eoxin predominantly produced by eosinophils, although mast cells and nasal polyps can also synthesize it. While its physiological roles are not well understood, 14,15-LTC4 exhibits limited contractile activity on guinea pig ileum and pulmonary parenchyma. However, it can increase vascular permeability in human endothelial cell monolayers in vitro with potency comparable to 5-LO-derived leukotrienes, contributing to plasma leakage characteristic of inflammation.

(±)14(15)-EET is a metabolite of arachidonic acid that is formed via epoxidation of arachidonic acid by cytochrome P450.[1],[2] It prevents increases in leukotriene B4, ICAM-1, and chemokine (C-C motif) ligand 1 (CCL2) induced by oxidized LDL in primary rat pulmonary artery endothelial cells (RPAECs) when used at a concentration of 1 μM.[3] (±)14(15)-EET induces dilation of preconstricted isolated canine coronary arterioles (EC50 = 0.2 pM).[4] It reduces myocardial infarct size as a percentage of the area at risk in a canine model of ischemia-reperfusion injury induced by left anterior descending coronary artery (LAD) occlusion when administered at a dose of 0.128 mg kg prior to occlusion or reperfusion.[5] Reference：[1]. Chacos, N., Falck, J.R., Wixtrom, C., et al. Novel epoxides formed during the liver cytochrome P-450 oxidation of arachidonic acid. Biochem. Biophys. Res. Commun. 104(3), 916-922 (1982).[2]. Oliw, E.H., Guengerich, F.P., and Oates, J.A. Oxygenation of arachidonic acid by hepatic monooxygenases. Isolation and metabolism of four epoxide intermediates. J. Biol. Chem. 257(7), 3771-3781 (1982).[3]. Jiang, J.-X., Zhang, S.-J., Xiong, Y.-K., et al. EETs attenuate ox-LDL-induced LTB4 production and activity by inhibiting p38 MAPK phosphorylation and 5-LO BLT1 receptor expression in rat pulmonary arterial endothelial cells. PLoS One 10(6), e0128278 (2015).[4]. Oltman, C.L., Weintraub, N.L., VanRollins, M., et al. Epoxyeicosatrienoic acids and dihydroxyeicosatrienoic acids are potent vasodilators in the canine coronary microcirculation. Circ. Res. 83(9), 932-939 (1998).[5]. Nithipatikom, K., Moore, J.M., Isbell, M.A., et al. Epoxyeicosatrienoic acids in cardioprotection: Ischemic versus reperfusion injury. Am. J. Physiol. Heart Circ. Physiol. 291(2), H537-H542 (2006).