Abstract
To estimate the effect of prednisolone on 5-lipoxygenase activity in eosinophils obtained from asthmatic patients, cytosolic levels of 5-H(P)ETE and Ca2+ were measured in the eosinophils which were exposed to prednisolone in vitro and in vivo. The mean level of 5-H(P)ETE during a wheezing attack was significantly lower in the patients who had received intravenous prednisolone (500 mg/day). Incubation with prednisolone in vitro caused a dose-dependent decrease in the cytosolic levels of 5-H(P)ETE and Ca2+ in eosinophils obtained during the wheezing attack, but not in the eosinophils obtained from during remission. Results suggest that prednisolone inhibits the level of 5-H(P)ETE in the eosinophil cytosols of asthmatic patients during a wheezing attack, probably by inhibition of 5-lipoxygenase activity which is involved in the reduction of the influx of Ca2+.
MeSH terms
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Adult
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Arachidonic Acids / antagonists & inhibitors*
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Arachidonic Acids / biosynthesis
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Asthma / blood
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Asthma / drug therapy*
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Calcium / metabolism
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Cytosol / chemistry
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Cytosol / drug effects
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Cytosol / metabolism
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Dose-Response Relationship, Drug
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Eosinophils / drug effects*
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Eosinophils / metabolism
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Eosinophils / ultrastructure
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Glucocorticoids / administration & dosage
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Glucocorticoids / pharmacology
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Glucocorticoids / therapeutic use*
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Humans
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Injections, Intravenous
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Leukocyte Count / drug effects
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Leukotriene C4 / antagonists & inhibitors
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Leukotriene C4 / metabolism
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Male
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Middle Aged
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Prednisolone / administration & dosage
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Prednisolone / pharmacology
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Prednisolone / therapeutic use*
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Remission Induction
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Respiratory Sounds / drug effects*
Substances
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Arachidonic Acids
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Glucocorticoids
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5-oxo-6,8,11,14-eicosatetraenoic acid
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Leukotriene C4
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Prednisolone
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Calcium