IMMUNOFLUORESCENCE ANALYSIS OF ANTISENSE OLIGODEOXYNUCLEOTIDE-MEDIATED KNOCK-DOWN OF THE MOUSE DELTA-OPIOID RECEPTOR IN-VITRO AND IN-VIVO

We have previously used antisense oligodeoxynucleotides (ODN) to the c loned delta opioid receptor (DOR) to inhibit the antinociceptive respo nse to spinally administered delta opioid receptor selective agonists in mice. Here we have examined the effect of DOR antisense ODN treatme nt on the level of DOR expressed in NG 108-15 cells and the spinal cor d, through immune-fluorescence microscopy, to determine the efficiency and selectivity of the antisense ODN-mediated 'knock-down' of the DOR in these tissues. Antisense ODN, but not mismatch control, treatment resulted in a significant reduction in DOR immunoreactivity (-ir) in N G 108-15 cells and spinal cord. Thus, the inhibition of antinociceptiv e response to intrathecal delta selective agonists by DOR antisense OD N correlates with the loss of DOR-ir in the superficial layers of the dorsal horn of the spinal cord.