Leukotrienes are a family of arachidonic acid metabolites with potent biological activities such as bronchoconstriction and leukocyte chemotaxis. Recent evidence has demonstrated that the 5-lipoxygenase (5-LO) and 5-lipoxygenase-activating protein (FALP) products of arachidonic acid metabolism, leukotriene C4, D4 and E4, were increased in the serum and the urine of asthmatic patients. Therefore, we examined the expression of 5-LO and FLAP mRNAs in the peripheral blood leukocytes (PBL) of 10 asthmatics and 10 controls. Both 5-LO and FLAP mRNAs of PBL in the asthmatic group were found to be significantly increased compared with those in the control group. These data suggest that up-regulation of 5-LO and FLAP mRNAs might be involved in the increased leukotriene synthesis and play an important role in the pathogenesis of asthma.
Copyright 1998 Academic Press.