The products of lipoxygenase metabolism of arachidonic acid, such as 12-(S)- and 15-(S)-hydroperoxyeicosatetraenoic acid, are released during asthma attacks and have a stimulatory effect on TRPV1.407 Another endogenous agonist of TRPV1, anandamide, is also synthesized in the lungs.408 The increased sensitivity of patients with COPD or asthma to inhaled capsaicin may explain the involvement of TRPV1 in the exacerbation of symptoms of these diseases.409. This evidence concerns the gene TRPV1 and chronic obstructive pulmonary disease.