The cysteinyl leukotrienes (CysLTs; LTC4, LTD4, and LTE4) contract airway and pulmonary vascular smooth muscle, increase vascular permeability, and stimulate mucus secretion, thereby playing a major role in asthma.1,2,3,4 LTC4, LTD4, and LTE4 mediate their actions via at least two receptors designated CysLT1 and CysLT2.1 Cloning of the human CysLT1 receptor reveals it is a 337 amino acid protein with a calculated molecular mass of 38,549.5 The rank order of binding for leukotrienes to the cloned receptor, as determined using a radioligand binding assay, is LTD4 >> LTC4 = LTE4 >> LTB4.5 The mRNA for the human CysLT1 receptor is expressed in spleen and peripheral blood leukocytes with smaller amounts in lung, placenta, and small intestine. Immunohistochemical studies reveal the receptor is expressed on eosinophils, mast cells, macrophages, neutrophils, and vascular endothelial cells in the nasal mucosa.6WARNING This product is not for human or veterinary use.
