Measurement and chromatographic characterization of prodynorphin-derived peptides in the guinea-pig ileum.

Guinea-pig ileum was dissected and the mucosa, submucosa and external musculature extracted with aqueous acetic acid for measurement of four prodynorphin-derived peptides, namely dynorphin A 1-8, dynorphin A 1-17, dynorphin B, and alpha-neoendorphin. The peptide-like immunoreactive material extracted from the external musculature was characterized by multi-dimensional chromatographic analysis and compared to synthetic porcine standards. The chromatographic methods utilized were: reversed-phase high performance liquid chromatography (RP-HPLC), using two different eluants; cation exchange high performance liquid chromatography (CE-HPLC) and gel filtration chromatography. The dynorphin A 1-8-like immunoreactive material was homogeneous and coeluted with the standard in all chromatographic modes. The dynorphin A 1-17-like and dynorphin B-like immunoreactive material was heterogeneous but showed a peak that coeluted with synthetic standard in all chromatographic modes. The alpha-neoendorphin-like immunoreactive material also appeared to be heterogeneous with the major component on CE-HPLC coeluting with the synthetic peptide standard while the major component on RP-HPLC eluted differently. It was concluded that the guinea-pig ileum contains immunoreactivity for peptides derived from all coding regions of the prodynorphin gene and that these peptides may be present in multiple immunoreactive forms.