Release of mast cell mediators, vasoconstriction and edema in the isolated, perfused head of the rat following intracarotid infusion of neurotensin.
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概要
Intracarotid infusions of neurotensin (NT) into the isolated, perfused head of rats trigger concentration-dependent histamine and 5-hydroxytryptamine (5-HT) release from the perfused organ. The secretory event was accompanied by a concentration-dependent rise in perfusion pressure and facilitation of edema formation. The three NT effects were markedly reduced in heads derived from rats pretreated with high doses of compound 48/80 to produce mast cell depletion. The vasoconstrictor response to NT was greatly attenuated by the 5-HT receptor antagonist methysergide but unaffected by antihistaminic drugs. The results were interpreted as an indication that NT stimulates histamine and 5-HT release from mast cells of the rat perfused head. The results also suggest that the vasoconstrictor response to NT in the rat head is mediated by mast cell 5-HT. The potentiation of edema formation by NT was attributed to the action of mast cell mediators (most likely histamine and 5-HT) released by NT on microvessels.