HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC RESOLUTION OF SYNTHETIC OPIATE AND ANTI-OPIATE PEPTIDES FROM HUMAN PLASMA

An assay system using reversed-phase high-performance liquid chromatog raphic (HPLC) resolution of synthetic anti-opioid peptides (AOPs) and opioid peptides (OPs) was developed. Samples were diluted with trifluo roacetic acid, loaded onto Sep-Pak C-18 cartridges, eluted, dried, and redissolved in ethanol-acetic acid-water. Retention-time consistency was established, and high levels of synthetic AOP and OP recovery, gen erally higher than 80%, were achieved. In a single HPLC run synthetic enkephalins, dynorphins, and beta-endorphins were separated even when extracted from human plasma using a volatile mobile phase which yielde d fractions totally compatible with quantitation by radioimmunossay. C ombining the resolution of HPLC with the sensitivity of radioimmunoass ay (RIA) may facilitate simultaneous measurement of numerous neuropept ides in body fluids such as plasma and cerebrospinal fluid.