PKC-epsilon translocation in enteric neurons and interstitial cells of Cajal in response to muscarinic stimulation

Am J Physiol Gastrointest Liver Physiol. 2003 Sep;285(3):G593-601. doi: 10.1152/ajpgi.00421.2002. Epub 2003 Apr 23.

Abstract

Interstitial cells of Cajal in the deep muscular plexus (ICC-DMP) of the small intestine express excitatory neurotransmitter receptors. We tested whether ICC-DMP are functionally innervated by cholinergic neurons in the murine intestine. Muscles were stimulated by intrinsic nerves and ACh and processed for immunohistochemistry to determine these effects on PKC-epsilon activation. Under control conditions, PKC-epsilon-like immunoreactivy (PKC-epsilon-LI) was only observed in myenteric neurons within the tunica muscularis. Electrical field stimulation or ACh caused translocation of neural PKC-epsilon-LI from the cytosol to a peripheral compartment. After stimulation, PKC-epsilon-LI was found in spindle-shaped cells in the DMP. These cells were identified as ICC-DMP by Kit-LI and vimentin-LI. PKC-epsilon-LI in ICC-DMP and translocation of PKC epsilon-LI in neurons were blocked by tetrodotoxin or atropine, suggesting that these responses were due to activation of muscarinic receptors. Western blots also confirmed translocation of PKC-epsilon-LI. In conclusion, PKC-epsilon translocation is linked to muscarinic receptor activation in ICC-DMP and a subpopulation of myenteric neurons. These studies demonstrate that ICC-DMP are functionally innervated by excitatory motoneurons.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acetylcholine / pharmacology
  • Animals
  • Atropine / pharmacology
  • Biological Transport / drug effects
  • Electric Stimulation
  • Enzyme Activation / drug effects
  • Intestine, Small / cytology
  • Intestine, Small / metabolism*
  • Mice
  • Mice, Inbred BALB C
  • Muscarinic Antagonists / pharmacology
  • Muscle, Smooth / cytology
  • Muscle, Smooth / metabolism
  • Myenteric Plexus / cytology
  • Myenteric Plexus / enzymology
  • Myenteric Plexus / metabolism*
  • Neurons / metabolism*
  • Protein Kinase C / metabolism*
  • Protein Kinase C-epsilon
  • Proto-Oncogene Proteins c-kit / metabolism
  • Receptors, Muscarinic / physiology*
  • Tetrodotoxin / pharmacology
  • Vimentin / metabolism

Substances

  • Muscarinic Antagonists
  • Receptors, Muscarinic
  • Vimentin
  • Tetrodotoxin
  • Atropine
  • Prkce protein, mouse
  • Proto-Oncogene Proteins c-kit
  • Protein Kinase C
  • Protein Kinase C-epsilon
  • Acetylcholine