Localization of GTP-binding protein Go in the enteric nervous system in rat ileum

The localization of a GTP-binding protein G(o) was examined immunohistochemically in rat ileum using antibodies against the alpha-subunit of G(o) (G(o) alpha). G(o) alpha-positive fibers clearly demonstrated the topography and structure of the enteric nervous system of the ileum. G(o) alpha was present only in the nervous system and was generally distributed both in synapse-rich and in nonsynaptic areas. The distribution of G(o) alpha in a nonsynaptic area suggests the possibility that G(o) may be involved not only in neurotransmission mechanisms but also in other functions.