ISOLATION AND IDENTIFICATION OF CGRP C-TERMINAL FRAGMENTS IN THE RAT SPINAL-CORD

In this study, we have used a liquid chromatography micropurification system in combination with fast atom bombardment mass spectrometry (FA B-MS) and N-terminal sequencing to characterize 3 calcitonin gene-rela ted peptide (CGRP) immunoreactivities present in the rat spinal cord. Full-length CGRP contributed to approximately 68% of the total immunor eactive material, while approximately 23% consisted of 2 C-terminal fr agments, CGRP(18-37) and CGRP(19-37). Synthetic C-terminal fragments o f CGRP, e.g. CGRP(19-37), have been shown to antagonize CGRP effects i n vitro. We show that such fragments exist in relatively substantial a mounts in the rat spinal cord.