A metabolite of substance P, SP7-11 is involved in the pathogenesis of inflammatory joint disease.

The possibility that neuropeptides, in particular members of the tachykinin family are involved in inflammatory joint disease is widely disputed. Both clinical and experimental observations indicate that the tachykinin substance P (SP) may be involved in the pathogenesis of arthritis. We have studied the effects of tachykinins and the metabolites of SP on chondrocyte function. We have shown that the C-terminal pentapeptide sequence; H-Phe-Phe-Gly-Leu-Met-NH2 is biologically active in bovine chondrocyte cultures. The production of SP7-11 is limited by hydrolysis of the intact peptide by neutral endopeptidase (E.C. 3.4.24.11). The regulation of this enzyme would modulate the activity of substance P on articular cartilage chondrocytes.