H3 receptors: modulation of histamine-stimulated neural pathways influencing electrogenic ion transport in the guinea pig colon.
The role of H3 receptors in neurally-evoked recurrent increases in chloride ion secretion evaluated from changes in short-circuit current (Isc) was examined during application of histamine or histamine analogs. Muscle-stripped or whole thickness segments of distal colon were set up in flux chambers. Histamine and dimaprit, an H2 receptor agonist, caused recurrent increases in Isc. Dimaprit-evoked recurrent responses were reduced by the H3 receptor agonists, N alpha-methylhistamine and R alpha-methylhistamine, and the inhibition was reversed by the H3 receptor antagonist, burimamide. Histamine-evoked recurrent increases in Isc were enhanced by the H3 receptor antagonists burimamide and thioperamide. The results indicate that H3 receptors play an inhibitory role in histamine-evoked, neurally-mediated recurrent increases in Isc in guinea pig colon.
Cooke
H J
HJ
Department of Physiology, Ohio State University, Columbus 43210.
Wang
Y Z
YZ
D000818:Animals; D018118:Chloride Channels / Q000187:drug effects / Q000378:metabolism*; D003106:Colon / Q000187:drug effects / Q000294:innervation* / Q000378:metabolism*; D017259:Dimaprit / Q000494:pharmacology; D004594:Electrophysiology; D006168:Guinea Pigs; D006632:Histamine / Q000031:analogs & derivatives / Q000494:pharmacology*; D017442:Histamine Agonists / Q000494:pharmacology; D006633:Histamine Antagonists; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009434:Neural Pathways / Q000187:drug effects; D011970:Receptors, Histamine H2 / Q000187:drug effects / Q000378:metabolism; D018100:Receptors, Histamine H3 / Q000502:physiology*
D018118:Chloride Channels; D017442:Histamine Agonists; D006633:Histamine Antagonists; D011970:Receptors, Histamine H2; D018100:Receptors, Histamine H3; D006632:Histamine; D017259:Dimaprit