THE EFFECT OF HISTAMINE ON ION TRANSPORT IN PORCINE JEJUNUM

Abstract Histamine is present in the gastrointestinal tract, and is an important mediator in gastrointestinal type I hypersensitivity reactions. The effect of histamine on ion transport in “stripped” porcine jejunal preparations was investigated. Histamine caused a transient increase in short-circuit current (SCC), which seemed to be concentration dependent. A maximum response was obtained at 0.1 mM. The histamine response was attenuated (44.8%) by the neuronal conduction blocker, tetrodotoxin (TTX), indicating that enteric neurotransmitters are involved. The neurokinin-1 antagonist, CP 99,994, did not alter the response to histamine (0.1 mM). Thus, tachykinins acting at NK-1 receptors do not seem to be involved in the histamine response.