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 cloned delta opioid receptor (DOR) to inhibit the antinociceptive response to spinally administered delta opioid receptor selective agonists in mice. Here we have examined the effect of DOR antisense ODN treatment on the level of DOR expressed in NG 108-15 cells and the spinal cord, through immuno-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 NG 108-15 cells and spinal cord. Thus, the inhibition of antinociceptive response to intrathecal delta selective agonists by DOR antisense ODN correlates with the loss of DOR-ir in the superficial layers of the dorsal horn of the spinal cord.

Effects of intrahypothalamic administration of antisense DNA for progesterone receptor mRNA on reproductive behavior and progesterone receptor immunoreactivity in female rat

Since reproductive behaviors of female rats can be correlated with estrogen-induced increases in progestin binding by hypothalamic neurons, we hypothesized that specific progesterone receptor (PR) antisense DNA sequences might decrease these behaviors. Antisense oligonucleotides (15 bases), spanning the translation start site of rabbit PR mRNA, were microinjected directly among ventromedial hypothalamic neurons, and their behavioral effects were compared to control oligonucleotides composed of the same nucleotide bases in scrambled order. When applied 12 but not 24 hr after estradiol, the PR antisense treatment significantly reduced iordosis behavior, measured either as a reflex or in a mating behavior test. Notably, proceptive behaviors, which are strongly progesterone dependent, were greatly reduced in their occurrence (80% decrease). To see if PR protein was also reduced, antisense DNA was administered near the ventromedial hypothalamus on one side of the brain, while the other side received the scrambled control sequence or vehicle. The total number of PR-immunoreactive cells on the antisense side was significantly lower in the ventromedial nucleus, but not in control measurements from the medial preoptic area. Interrupting gene expression for PR, a transcription factor, in hypothalamic neurons, can have behavioral and immunocytochemical effects.