Prednisolone inhibits synthesis of 5-H(P)ETE in eosinophils from asthmatic patients during a wheezing attack but not during remission.
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+.
Shindo
K
K
First Department of Internal Medicine, Yokohama City University School of Medicine, Yokohama, Japan.
Machida
M
M
Fukumura
M
M
Koide
K
K
D000328:Adult; D001095:Arachidonic Acids / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D001249:Asthma / Q000097:blood / Q000188:drug therapy*; D002118:Calcium / Q000378:metabolism; D003600:Cytosol / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004804:Eosinophils / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007275:Injections, Intravenous; D007958:Leukocyte Count / Q000187:drug effects; D017997:Leukotriene C4 / Q000037:antagonists & inhibitors / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011239:Prednisolone / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D012074:Remission Induction; D012135:Respiratory Sounds / Q000187:drug effects*
D001095:Arachidonic Acids; D005938:Glucocorticoids; C080828:5-oxo-6,8,11,14-eicosatetraenoic acid; D017997:Leukotriene C4; D011239:Prednisolone; D002118:Calcium