Expression of leukotriene C4 synthase mRNA by the choroid plexus in mouse brain suggests novel neurohormone functions of cysteinyl leukotrienes

Leukotriene C(4) is a potent mediator of allergic and inflammatory reactions, and is formed from arachidonic acid and glutathione through the sequential action of 5-lipoxygenase and leukotriene C(4) synthase (LTCS). These enzymes are predominantly expressed in cells of myeloid lineage. In this report, we have investigated LTCS mRNA expression in mouse brain. Expression was demonstrated using RT-PCR and RNase protection assays. In situ hybridization experiments showed exclusive staining of the choroid plexus of all brain ventricles. This expression pattern may provide a mechanism for the generation of LTC(4) on the cerebral side of the blood-brain barrier and suggests a possible novel regulator function of LTC(4) in the formation of cerebrospinal fluid.