Tachykinin regulation of serotonin release: enhancement of [ 3H]serotonin release from rat cerebral cortex by neuromedin K and substance P acting at distinct receptor sites

Abstract

Neuromedin K and substance P (SP) enhanced the basal (5 mM K +) and potassium-evoked (40 mM K +) release of [ 3H]5-hydroxytryptamine ([ 3H]5-HT) from slices of the rat cerebral cortex. The effects of the two tachykinins were additive. The SP antagonist spantide ([ d-Arg 1, d-Trp 7,9, Leu 11]-SP) (10 −6M) inhibited the stimulatory effect of SP but not of neuromedin K on the release of [ 3H]5-HT. These findings suggest that the two tachykinins exhibit effects on serotonin release at distinct receptor sites.