NK-3 receptors mediate enhancement of substance P release from capsaicin-sensitive spinal cord afferent terminals

摘要

The effects of NK-3 receptor agonists on the release of substance P-immunoreactivity(SP-LI) have been investigated using superfused rat spinal cord synaptosomes. The Ca~2+ -dependent overflow of SP-LI evoked by 35 mM KCl was concentration-dependently Enhanced by senktide(EC_50=52 nM; maximal effect =70/100)or [MePhe~7]NKB (EC_50 =5.5 nM; maximal Effect=125/100), both selective agonists at receptors of the NK-3 type. The potentiation of the SP-LI overflow elicited by 100 nM senktide or [MePhe~7]NKB was prevented By the NK-3 receptor antagonist (+)-SR142801.