Influence of substance P on nociception and stress

In 1980 Oehme and co-workers [11] reported that Substance P (SP) has a dual effect on nociception, which is related to the pain threshold before SP administration. Our recent results showed that the N-terminal part of the SP sequence may be important to the hyperalgesic action, and the C-terminal part to the analgesic action of this peptide. The hyperalgesic effect of SP (and N-terminal fragments of SP) seems to be related to the "anti-stress" effect which was first demonstrated by Hecht and co-workers [5] and Oehme and co-workers [12]. Interaction of SP with opioid peptides could be the common reason of both the "anti-stress" effect and the hyperalgesic activity of SP.