Identification of neuropeptide FF-related peptides in rodent spinal cord

Peptides which should be generated from the neuropeptide FF (NPFF) precurso r were identified in mouse and rat spinal cord, by using reverse phase high pressure liquid chromatography with radioimmunoassay and electrospray mass spectrometry detection. In both species, two octapeptides, NPFF (Phe-Leu-P he-Gln-Pro-Gln-Arg-Phe-amide) and NPSF (Ser-Leu-Ala-Ala-Pro-Gln-Arg-Phe-ami de) were identified but a longer peptide NPA-NPFF (Asn-Pro-Ala-Phe-Leu-Phe- Crln-Pro-Gln-Arg-Phe-amide) was present at the highest concentration in rat spinal cord. In mouse, the homologous peptide, SPA-NPFF (Ser-Pro-Ala-Phe-L eu-Phe-Gln-Pro-Gln-Arg-Phe-amide) was not detected. Both peptides NPFF and NPSF reverse morphine-induced analgesia in the tail flick test. Our data re veal species differences in the maturation of NPFF precursor. (C) 2001 Else vier Science Inc. All rights reserved.