Constricting effect of leukotrienes on cerebral arterioles of mice

Three leukotrienes (LTB4, C4, D4 were locally applied to cerebral arterioles in doses varying from 3 × 10-8 to 4 ×  10-7M and each produced a dose related constriction. LTC was tested in the presence and absence of FPL-55712, a relatively specific inhibitor of leukotriene receptors. A low dose (10-8M) of FPL-55712 did markedly reduce the response to the LTC and did not significantly alter an equally pronounced constriction produced by norepinephrine. The constricting properties of the leukotrienes shown by our data support the suggestion that these products of lipoxygenase’s action on arachidonic acid have the potential to modify cerebrovascular tone. This potential may be important in view of recent evidence showing that the brain can make significant amounts of leukotrienes from arachidonic acid.