当前位置： SCI文献检索 > EUROPEAN JOURNAL OF PHARMACOLOGY期刊下所有文献 > Modulatory effect of imetit, a histamine H3 receptor agonist, on C-fibers, cholinergic fibers and mast cells in rabbit lungs in vitro.

Modulatory effect of imetit, a histamine H3 receptor agonist, on C-fibers, cholinergic fibers and mast cells in rabbit lungs in vitro.

Abstract：

:The pharmacological mechanisms involved in the interactions between C-fibers, cholinergic fibers and mast cells were investigated in tracheally perfused rabbit lungs by measuring the simultaneous release of substance P and histamine in lung effluents. The amounts of substance P and histamine released in lung superfusates were measured by radioimmunoassay (RIA) after administration of capsaicin and carbachol. Capsaicin (10(-4) M) induced a simultaneous increase in substance P (273 +/- 56% of baseline) and histamine (460 +/- 138%) release. Similarly, carbachol (10(-4) M) caused an increase in the release of both substance P (367 +/- 111%) and histamine (1379 +/- 351%). The effect of capsaicin was prevented by pretreating the lungs with the tachykinin NK1 receptor antagonist SR 140333 (10(-7) M), and atropine (10(-6) M). SR 140333 prevented the carbachol-induced release of substance P but not of histamine. Exogenous substance P induced an increase in histamine release (136 +/- 7%) which was significantly greater in lungs perfused with the neutral endopeptidase inhibitor, thiorphan (10(-5) M) (272 +/- 35%). This effect was prevented by atropine (10(-6) M). Pretreatment of lungs with imetit (5 x 10(-8) M), a selective H3 receptor agonist, prevented the capsaicin-induced release of both mediators. Imetit also blocked the carbachol-induced release of substance P but not of histamine. Exogenous substance P-evoked histamine release was inhibited by imetit. Therefore, it can be concluded that substance P released through the action of capsaicin can activate cholinergic fibers, leading to cholinoceptor stimulation with subsequent activation of C-fibers and mast cells. While the presence of presynaptic H3 receptors modulating substance P-induced acetylcholine release was only surmised, the existence of modulating histamine H3 receptors on C-fibers was confirmed.

journal_name

Eur J Pharmacol

journal_title

European journal of pharmacology

authors

Nemmar A,Delaunois A,Beckers JF,Sulon J,Bloden S,Gustin P

doi

10.1016/s0014-2999(99)00176-4

keywords:

subject

Has Abstract

pub_date

1999-04-23 00:00:00

pages

23-30

issue

eissn

0014-2999

issn

1879-0712

pii

S0014-2999(99)00176-4

journal_volume

371

pub_type

杂志文章

在线工具

Modulatory effect of imetit, a histamine H3 receptor agonist, on C-fibers, cholinergic fibers and mast cells in rabbit lungs in vitro.