Metabolic profiling of opioid peptides in tooth pulp by HPLC and radioreceptor assay.

A analytical system using a combination of gradient RP-HPLC and radioreceptor assay as the HPLC-detector is used to analyze the peptide-rich fraction extracted from a canine tooth pulp homogenate and to provide a metabolic profile of endogenous receptoractive peptides. The gradient RP-HPLC effectively separates the endogenous peptide mixture into a range of hydrophobicities that corresponds to a spectrum of peptide sizes. The receptor preparation is derived from a canine limbic system synaptosome fraction. 3H-DADL serves as the ligand in the RRA. The RP-HPLC/RRA data indicate canine tooth pulp contains a wide range of peptides that interact with the opioid peptide receptor preparation and displace the delta-receptor preferring ligand D2-ala, D5-Leu leucine enkephalin.