好中球活性化における5-hydroperoxy-eicosatetraenoic acid (5-HPETE) の役割

抄録

Hydroperoxyeicosatetraenoic acids (HPETEs), hydroperoxy intermediates of arachidonic acid, have been recently reported to play an important role in regulating and modulating various cell functions such as secretion of hormones.
As for neutrophils, 5-HPETE produced by various stimuli is known to enhance the function of primary stimulus such as FMLP. In the present study, we firstly confirmed that 5-HPETE enhanced FMLP-stimulated superoxide generation, which was chosen as one of neutrophil functions. In order to clarify the possible mechanism of the enhancing effect of 5-HPETE, we measured the increase in cytosolic free calcium, which is thought to be necessary for FMLP-stimulated neutrophil activation, using fura-2-loaded human neutrophils. We have shown that 5-HPETE dose-dependently augumented FMLP-stimulated increase in cytosolic free calcium without converting to LTB₄. 5-HPETE had no effect on ³H-FMLP binding to human neutrophils.
The present data suggested that 5-HPETE by itself would enhance FMLP-stimulated increase in cytosolic free calcium, which resulted in neutrophil activation.