CRF microinjected into the dorsal vagal complex inhibits TRH analog- and kainic acid-stimulated gastric contractility in rats.
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.
Department Psychiatry and Research, West Los Angeles Veterans Administration Medical Center, CA.
I
I
Heymann-Mönnikes
Y
Y
Taché
M
M
Trauner
H
H
Weiner
T
T
Garrick
D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005769:Gastrointestinal Motility / Q000187:drug effects*; D007608:Kainic Acid / Q000494:pharmacology*; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology*; D008845:Microinjections; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D009928:Organ Specificity; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D011903:Raphe Nuclei / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D013270:Stomach / Q000187:drug effects / Q000502:physiology; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D014630:Vagus Nerve / Q000187:drug effects / Q000502:physiology*
D013973:Thyrotropin-Releasing Hormone; C027979:L-pyroglutamyl-L-histidyl-3,3-dimethylprolinamide; D003346:Corticotropin-Releasing Hormone; D007608:Kainic Acid; D011761:Pyrrolidonecarboxylic Acid