Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The inhalation of platelet activating factor (PAF) produces bronchoconstriction in normal and asthmatic subjects. To identify the mechanism by which PAF-induced bronchoconstriction occurs in humans, bronchoprovocation testing was performed in 7 subjects (3 normal, 4 with mild asthma) after pretreatment with phosphate-buffered saline (PBS), atropine, chlorpheniramine, or indomethacin. We determined the nebulizer concentration of PAF which reduced specific airway conductance (SGaw) 35% (PC35 SGaw) and the slope of the PAF dose-response curve. Atropine produced baseline bronchodilatation (SGaw increased 50%), while chlorpheniramine and indomethacin had no effect on baseline pulmonary function. Atropine increased airway responsiveness to PAF: the PC35 SGaw decreased 40% (p less than 0.05) and the slope of the PAF dose-response curve increased 86% (p less than 0.05). In contrast, chlorpheniramine inhibited the airway response to PAF: the PC35 SGaw increased 87% (p less than 0.05), while the slope of the PAF dose-response curve decreased an insignificant 37%. Indomethacin did not affect either measurement. Chlorpheniramine also prevented the PAF-induced facial flushing and feeling of warmth; atropine and indomethacin did not. These results suggest that PAF-induced bronchoconstriction in humans is mediated at least in part by histamine release, not by cholinergic or cyclooxygenase-dependent mechanisms. Other indirect effects, such as the release of sulfidopeptide leukotrienes, or a direct effect on airway smooth muscle may also contribute to PAF-induced bronchoconstriction. Why atropine heightened the airway response to PAF is unclear.
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PMID:Mechanism of platelet activating factor-induced bronchoconstriction in humans. 319

A patient with the carcinoid syndrome had flushes provoked by the ingestion of water at 60 degrees C, red wine, and milk chocolate. The patient was given sequential courses of clonidine hydrochloride, chlorpheniramine maleate, cimetidine, and a combination of chlorpheniramine and cimetidine. No flushes followed ingestion of red wine or milk chocolate during treatment courses with cimetidine (alone or in combination with chlorpheniramine) or clonidine. Chlorpheniramine alone did not affect flushing. None of the pharmacologic agents altered the flushing response to the ingestion of water at 60 degrees C.
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PMID:Blockade of carcinoid flush with cimetidine and clonidine. 705 11