Nitric oxide mediated formation of cyclic GMP in the olfactory system

OLFACTORY cilia preparation from rats contain considerable activity of soluble guanylate cyclase as indicated by the formation of cyclic GMP (cGMP) upon application of nitroprusside, a nitric oxide generating agent. Stimulation of olfactory cilia with high doses of odorants elicited a delayed and sustained elevation of the cGMP-concentration. The odorant-induced cGMP-response was abolished by L-N-nitro-arginine, a selective inhibitor of nitric oxide synthesis, as well as by haemoglobin which efficiently binds and inactivates nitric oxide. These observations suggest that the NO/cGMP cascade may plan an important role in signal processing of the olfactory system.