Table 5.

Preclinical in vitro and in vivo experiments with H₄ receptor ligands in visceral sensory signalling and nociception

Model	Species	In vitro/in vivo	Ligand	Effect	Ref
Submucous plexus neurons	Human	In vitro	4-methylhistamine	4-methylhistamine-induced excitation reduced by JNJ7777120	Breunig et al. (2007)
			JNJ7777120
Jejunal afferent firing	Rat	In vitro	Thioperamide	Thioperamide reduced histamine-induced jejunal afferent firing	Brunsden and Grundy (1999)
Jejunal afferent firing	Rat	In vivo	Thioperamide	No effect on histamine-induced jejunal afferent firing	Kreis et al. (1998)
Post-inflammatory visceral hypersensitivity	Rat	In vivo	JNJ7777120	JNJ7777120 dose-dependently reversed visceral hypersensitivity	Deiteren et al. (2014)

4-methylhistamine, H₄ receptor agonist; JNJ7777120, H₄ receptor antagonist; thioperamide, H₃ and H₄ receptor antagonist.