Peripheral CRF activates myenteric neurons in the proximal colon through CRF(1) receptor in conscious rats.

Abstract

Corticotropin-releasing factor (CRF) injected peripherally induces clustered spike-burst activity in the proximal colon through CRF(1) receptors in rats. We investigated the effect of intraperitoneal CRF on proximal colon ganglionic myenteric cell activity in conscious rats using Fos immunohistochemistry on the colonic longitudinal muscle/myenteric plexus whole mount preparation. In vehicle-pretreated rats, there were only a few Fos immunoreactive (IR) cells per ganglion (1.2 +/- 0.6). CRF (10 microg/kg ip) induced Fos expression in 19.6 +/- 2.1 cells/ganglion. The CRF(1)/CRF(2) antagonist astressin (33 microg/kg ip) and the selective CRF(1) antagonist CP-154,526 (20 mg/kg sc) prevented intraperitoneal CRF-induced Fos expression in the proximal colon (number of Fos-IR cells/ganglion: 2.7 +/- 1.2 and 1.0 +/- 1.0, respectively), whereas atropine (1 mg/kg sc) had no effect. Double labeling of Fos with protein gene product 9.5 revealed the neuronal identity of activated cells that were encircled by varicose fibers immunoreactive to vesicular acetylcholine transporter. Fos immunoreactivity was mainly present in choline acetyltransferase-IR nerve cell bodies but not in the NADPH-diaphorase-positive cells. These results indicate that peripheral CRF activates myenteric cholinergic neurons in the proximal colon through CRF(1) receptor.

• Authors: Marcel Miampamba, Celine Maillot, Mulugeta Million, Yvette Taché
• Journal: American journal of physiology. Gastrointestinal and liver physiology (Am J Physiol Gastrointest Liver Physiol) Vol. 282 Issue 5 Pg. G857-65 (May 2002) ISSN: 0193-1857 [Print] United States
• PMID: 11960782 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• CP 154526
• Proto-Oncogene Proteins c-fos
• Pyrimidines
• Pyrroles
• Receptors, Corticotropin-Releasing Hormone
• CRF receptor type 1
• Corticotropin-Releasing Hormone
• NADPH Dehydrogenase
• Acetylcholine

Topics

• Acetylcholine (metabolism)
• Animals
• Colon (innervation)
• Consciousness
• Corticotropin-Releasing Hormone (pharmacology)
• Injections, Intraperitoneal
• Male
• Myenteric Plexus (cytology, drug effects, physiology)
• NADPH Dehydrogenase (analysis)
• Neurons (chemistry, enzymology)
• Proto-Oncogene Proteins c-fos (analysis)
• Pyrimidines (pharmacology)
• Pyrroles (pharmacology)
• Rats
• Rats, Sprague-Dawley
• Receptors, Corticotropin-Releasing Hormone (antagonists & inhibitors, metabolism)