Neuronal histamine in the gut wall releasable by gastrin and cholecystokinin.
Histamine accumulated in the ligated vagus nerve of the rat, both above and below the ligature; maximum accumulation was after 4 h. The finding is suggestive of axonal flow. Further evidence for histamine in peripheral nerves was obtained in experiments showing that the guinea-pig gut wall could be labelled with [3H]histamine. The experiments were carried out with isolated strips of stomach wall and taenia coli. Electrical stimulation released [3H]histamine from these specimens. The release could be blocked by Ca2+-free medium or by tetrodotoxin. The release was unaffected by vagal denervation or chemical sympathectomy (6-hydroxydopamine) but prevented by reserpinization. Gastrin-17 and cholecystokinin-39 released radioactivity by a tetrodotoxin-sensitive mechanism. The possible existence of a gastrin/cholecystokinin-sensitive neuronal pool of histamine in the gut wall offers a new perspective on the postulated role of histamine as a physiological stimulant of gastric acid secretion and might explain why H2-receptor antagonists block gastrin-stimulated acid secretion.
D000818:Animals; D002766:Cholecystokinin / Q000494:pharmacology* / Q000031:analogs & derivatives; D003106:Colon / Q000294:innervation*; D004558:Electric Stimulation; D005755:Gastrins / Q000494:pharmacology*; D006168:Guinea Pigs; D006632:Histamine / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology*; D013270:Stomach / Q000294:innervation*; D009435:Synaptic Transmission / Q000187:drug effects; D014630:Vagus Nerve / Q000187:drug effects
D005755:Gastrins; D010446:Peptide Fragments; C013550:gastrin 17; C032740:cholecystokinin 39; D006632:Histamine; D002766:Cholecystokinin