Conversion rate of leukotriene C4 to Leukotriene E4 is decreased in children with asthma

Abstract

Cysteinyl leukotrienes (cysLTs; LTC4, LTD4, and LTE4) are important mediators in asthma. LTC4 is metabolized to less active LTE4 via LTD4 by glutamyl transpeptidases and dipeptidases. The enzymatic conversion of LTC4 to LTE4 may be a regulatory mechanism in asthma. We examined the conversion rate of LTC4 to LTE4 in children it to asthma, and compared it to that in controls. After serum specimens from children with asthma were incubated with exogenous LTC4 for 30 minutes at 37°C, the levels of LTC4 and LTE4 were measured by high-performance liquid chromatography. Conversion rate of LTC4 to LTE4 was significantly lower in children with asthma (67.6 ± 4.8 LTE4 ng/mg of protein per minute) than controls (86.8 ± 4.4 LTE4 ng/mg of protein per minute). The result indicates that the conversion rate of LTC4 to LTE4 may contribute to the pathogenesis of childhood asthma.