Monoclonal antibodies specific for ohmefentanyl

Ohmefentanyl (Ohm, N[1-(beta-hydroxy-beta-phenylethyl)-3-methyl-4- piperidyl]-N-phenylpro-pronamide), designed and synthesized by our laboratory, is a highly selective mu receptor agonist. After somatic cell fusion between splenocytes of BALB c mice, immunized by Ohm-BSA conjugate and NS-1 myeloma cells, 2 lines of hybridoma (D2 and F4) secreting monoclonal anti-Ohm antibodies (MAb) were obtained. Saturation and competition experiments showed that MAb-D2 and MAb-F4 bound to Ohm-BSA with high affinity and high specificity. Using radioligand binding assay and bioassay, we also found that MAb-D2 and MAb-F4 inhibited [3H] Ohm binding to rat brain opioid receptors in a dose-dependent manner and antagonized the effect of Ohm on the contraction of guinea pig ileum induced by electric field stimulation. These results suggested that MAb-D2 and MAb-F4 were 2 monoclonal antibodies specific for Ohm and could be useful as functional antagonists of Ohm.