Bradykinin and capsaicin stimulate cyclic GMP production in cultured rat dorsal root ganglion neurons via a nitrosyl intermediate

Dorsal root ganglion (DRG) neurons express receptors for bradykinin and capsaicin, both algesic substances. Administration of bradykinin or capsaicin to neurons cultured from embryonic rat DRG stimulated the production of cyclic GMP but in nonneuronal DRG cultures. Bradykinin‐evoked Cyclic GMP production was mediated by B2 receptors and was unaltered by indomethacin. Both bradykinin‐ and capsaicin‐stimulated cyclim GMP production required Ca2+ and was inhibited by methylene blue. Furthermore, methylene blue attenuated basal cyclic GMP production in DRG neurons, suggesting tonic cyclic GMP production in these Cells. L‐NG‐monomethyl arginine inhibited both bradykinin‐and capsaicin‐stimulated cylic GMP production as well as basal cyclic GMP production. These findings suggest the involvement of a nitrosyl compound in bradykinin‐and capsaicinstimulated cyclic GMP production and in tonic cyclic GMP production in DRG Neurons. © 1993 Wiley‐Liss, Inc.