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 e osinophils obtained from asthmatic patients, cytosolic levels of 5-H(P )ETE and Ca2+ were measured in the eosinophils which were exposed to p rednisolone 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 recei ved intravenous prednisolone (500 mg/day). Incubation with prednisolon e 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 s uggest that prednisolone inhibits the level of 5-H(P)ETE in the eosino phil cytosols of asthmatic patients during a wheezing attack, probably by inhibition of 5-lipoxygenase activity which is involved in the red uction of the influx of Ca2+.