Substance P in the central nervous system.

A radioimmunoassay has been developed for measuring substance P-like immunoreactivity. Assay sensitivity was 0.7fmoles of substance P. Using the radioimmunoassay substance P-like immunoreactivity was detected in postmortem tissue samples from the central nervous system of rats and humans. Immunofluorescence studies confirmed the localisation of substance P in the dorsal horn of the spinal cord.