The effect of L-arginine and L-citrulline on NOx production in primary human airway epithelial cells exposed to asymmetric dimethylarginine (ADMA)

We determine: 1) whether the addition of asymmetric dimethylarginine (ADMA) reduces nitric oxide (NO)-related metabolites in primary airway epithelial cells under IL-13/ IFNγ stimulation, 2) supplementation of L-arginine/L-citrulline to cultures with high ADMA/iNOS expression is able to redirect iNOS towards NOx production. L-arginine and L-citrulline supplementation are able to increase the formation of NOx (nitrates + nitrates) in human airway epithelial cells, despite treatment with endogenous iNOS inhibitor ADMA. L-arginine and L-citrulline may have a therapeutic potential in diseases in which there is a defective production of NO.