Thyrotropin-releasing hormone analogue and serotonin interact within the dorsal vagal complex to augment gastric acid secretion.
The effects of serotonin (5HT) and a thyrotropin-releasing hormone (TRH) analogue, RX77368, on vagal control of gastric acid secretion were studied. Microinjection of RX77368 (0.66 pmol in 10 nl), but not 5HT (8 pmol in 10 nl), into the dorsal vagal complex (DVC) evoked a significant increase in acid output. When the same doses of RX77368 and 5HT were co-injected, the amount of acid secreted was significantly greater than that due to RX77368 alone. Thus, 5HT and the TRH analogue interact within the DVC to enhance vagal stimulation of acid secretion. The study suggests a possible functional significance of raphe TRH/serotonergic tracts projecting to the DVC.
McTigue
D M
DM
Department of Physiology, Ohio State University, College of Medicine, Columbus 43210.
Rogers
R C
RC
Stephens
R L
RL
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism*; D008297:Male; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000494:pharmacology*; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D014630:Vagus Nerve / Q000187:drug effects*
D012701:Serotonin; D013973:Thyrotropin-Releasing Hormone; C027979:L-pyroglutamyl-L-histidyl-3,3-dimethylprolinamide; D001285:Atropine; D011761:Pyrrolidonecarboxylic Acid