Histaminergic involvement in thyrotropin-releasing hormone stimulation of antral tissue in the rat.
The mechanism of action of thyrotropin-releasing hormone on antral motility was investigated in vitro. With the recent detection of thyrotropin-releasing hormone in gastrointestinal tissue, the possibility exists that the peptide may play a physiologic role in gastrointestinal motility. Results indicate that the hormone stimulates antral motility through a non-cholinergic excitatory pathway based on the inability of the muscarinic antagonist, atropine, to block the response. A histaminergic pathway is an attractive possibility to explain the excitatory response, because both pyrilamine and cimetidine inhibit the thyrotropin-releasing hormone induced response and the peptide has no further influence on antral motility after the tissue is exposed to a supramaximal concentration of histamine.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001626:Bethanechol Compounds / Q000494:pharmacology; D002927:Cimetidine / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D011706:Pyloric Antrum / Q000187:drug effects / Q000502:physiology*; D011738:Pyrilamine / Q000494:pharmacology; D051381:Rats; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
D001626:Bethanechol Compounds; D013973:Thyrotropin-Releasing Hormone; D001285:Atropine; D002927:Cimetidine; D006632:Histamine; D011738:Pyrilamine