5-Lipoxygenase-activating protein homodimer in human neutrophils: evidence for a role in leukotriene biosynthesis.

FLAP (5-lipoxygenase-activating protein) is a nuclear transmembrane protein involved in the biosynthesis of LTs (leukotrienes) and other 5-LO (5-lipoxygenase) products. However, little is known about its mechanism of action. In the present study, using cross-linkers, we demonstrate that FLAP is present as a monomer and a homodimer in human PMN (polymorphonuclear cells).

Histamine-induced inhibition of leukotriene biosynthesis in human neutrophils: involvement of the H2 receptor and cAMP.

1. Histamine is generally regarded as a pro-inflammatory mediator in diseases such as allergy and asthma. A growing number of studies, however, suggest that this autacoid is also involved in the downregulation of human polymorphonuclear leukocyte (PMN) functions and inflammatory responses through activation of the Gs-coupled histamine H(2) receptor.