Leukotrienes B4and C4in MS

Release of leukotriene B4 (LTB4) and leukotriene C4 (LTC4) from neutrophils and platelet-neutrophil suspensions in response to ionophore A23187 was measured in 12 multiple sclerosis (MS) patients and 8 healthy volunteers. LTC4 release from neutrophils, as well as from platelet-neutrophil suspensions, was significantly decreased in MS patients compared with the controls. There was no significant difference in the release of LTB4 between MS patients and controls. The findings suggest that permanent stimulation of platelets and neutrophils e.g., by encephalitogenic peptide leads to continuous LTC4 release with subsequent depletion of intracellular substrates serving as precursors for the formation of 5-lipoxygenase products. Since the target of microvascular actions of LTC4 are postcapillary venules, the release of this sulfidopeptide leukotriene might play a pathogenetic role in the formation of MS lesions.