S-nitrosothiols in respiratory biology

S-Nitrosothiol (SNOs) are nitric oxide (NO)-thiol adducts that mediate several cell and organ system signaling pathways relevant to respiration. SNOs are more selective and potent than NO in mediating many respiratory bioactivities, ranging from airway smooth muscle relaxation to regulation of central ventilatory drive [1-3]. Under physiological conditions, SNOs are also more stable and less cytotoxic than are NO and other bioactive nitrogen oxides [3, 4]. Their broad range of bioactivities arises, in part, from their potential to act stereoselectively [2], as nitrosonium (NO+) donors, as nitroxyl (NO-) donors or as NO radical donors [5]. Additionally, specific cell systems regulate the bioactivity of SNOs by modifying their synthesis, breakdown and localization [2, 4, 6, 7].