The regional distribution of somatostatin, substance P and neurotensin in human brain.

The regional distribution of somatostatin-, substance P- and neurotensin-like immunoreactivity was determined in 41 areas of 10 human brains. Each peptide is distributed widely in the human central nervous system and for each the pattern of distribution is unique. No significant relationship was found between peptide levels and patient age, interval between death and autopsy, and tissue storage time prior to assay. The regional distribution of these peptides is similar to that seen in several animal species and the pattern of this distribution is consistent with the idea that peptides function as neurotransmitters within the central nervous system. The problems of using human post-mortem material for peptide assay are discussed.