To be used in conjunction with Caymans CysLT1 receptor polyclonal antibody (Catalog No. 120500) to block protein-antibody complex formation during analysis for the CysLT1 receptor. Each vial contains 200 g of lyophilized peptide derived from the human CysLT1 protein sequence. The cysteinyl leukotrienes (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 2 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.