Stimulation of the neurokinin 3 receptor activates protein kinase Cε and protein kinase D in enteric neurons

Abstract

Tachykinins, acting through NK3 receptors (NK3R), contribute to excitatory transmission to intrinsic primary afferent neurons (IPANs) of the small intestine. Although this transmission is dependent on protein kinase C (PKC), its maintenance could depend on protein kinase D (PKD), a downstream target of PKC. Here we show that PKD1/2-immunoreactivity occurred exclusively in IPANs of the guinea pig ileum, demonstrated by double staining with the IPAN marker NeuN. PKCε was also colocalized with PKD1/2 in IPANs. PKCε and PKD1/2 trafficking was studied in enteric neurons within whole mounts of the ileal wall. In untreated preparations, PKCε and PKD1/2 were cytosolic and no signal for activated (ph..