Effects of tachykinins on [3H]taurine release from human astrocytoma cells (U-373 MG)

Abstract

Substance P (SP) stimulated [3H]taurine release from human astrocytoma cells (U-373 MG). This effect was concentration dependent and the EC50 was 0.3 nM. This stimulatory effect of SP can be inhibited by spantide, a SP receptor antagonist. The rank order of potencies of related tachykinins and their analogues in stimulating the release of [3H]taurine was SP≫neurokinin A≫neurokinin B and [Glp6,l-Pro9]SP (6-11) ≫ [Glp6, d-Pro9]SP (6-11)_which conformed to that reported for the tachykinin NK-1 receptor. In addition to SP, isoproterenol a β-adrenergic agonists, can also increase the release of [3H]taurine from these cells and the effects of SP and isoproterenol were additive. © 1991.