CRF microinjected into the dorsal vagal complex inhibits TRH analog- and kainic acid-stimulated gastric contractility in rats

Brain Res. 1991 Jul 19;554(1-2):139-44. doi: 10.1016/0006-8993(91)90181-t.

Abstract

The effect of CRF microinjected into the dorsal vagal complex (DVC) on centrally-stimulated gastric contractility was investigated in fasted, urethane-anesthetized rats. Miniature strain gauge force transducers were acutely implanted on the corpus of the stomach and contractility was analyzed by computer. Microinjection of the stable thyrotropin-releasing hormone (TRH) analog, RX 77368, (26 pmol) into the DVC induced a 12.2-fold stimulation of gastric contractility within 30 min. Corticotropin-releasing factor (CRF) (63-210 pmol) microinjected into the DVC concomitantly with RX 77368 (26 pmol) induced a dose-related inhibition of stimulated gastric contractility. Neither CRF alone (210 pmol) nor vehicle modified basal gastric contractility. Microinjection of kainic acid (141 pmol) into the raphe pallidus nucleus induced a 3.6-fold stimulation of gastric contractility after 45 min. This stimulation was suppressed by bilateral microinjection of CRF (105 pmol/site) into the DVC. These results demonstrate that CRF acts in the DVC to inhibit centrally-stimulated gastric contractility and suggest that TRH and CRF may interact in the DVC to regulate gastric motor function.

Publication types

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

MeSH terms

  • Animals
  • Corticotropin-Releasing Hormone / administration & dosage
  • Corticotropin-Releasing Hormone / pharmacology*
  • Dose-Response Relationship, Drug
  • Gastrointestinal Motility / drug effects*
  • Kainic Acid / pharmacology*
  • Male
  • Medulla Oblongata / drug effects
  • Medulla Oblongata / physiology*
  • Microinjections
  • Muscle Contraction / drug effects
  • Muscle, Smooth / drug effects
  • Muscle, Smooth / physiology
  • Organ Specificity
  • Pyrrolidonecarboxylic Acid / analogs & derivatives
  • Raphe Nuclei / drug effects
  • Raphe Nuclei / physiology
  • Rats
  • Rats, Inbred Strains
  • Stomach / drug effects
  • Stomach / physiology
  • Thyrotropin-Releasing Hormone / analogs & derivatives*
  • Thyrotropin-Releasing Hormone / pharmacology
  • Vagus Nerve / drug effects
  • Vagus Nerve / physiology*

Substances

  • Thyrotropin-Releasing Hormone
  • L-pyroglutamyl-L-histidyl-3,3-dimethylprolinamide
  • Corticotropin-Releasing Hormone
  • Kainic Acid
  • Pyrrolidonecarboxylic Acid