Figure 6.

Blockade by DOR-AS-1 antisense oligonucleotides of [D-Ala²]Deltorphin-(Deltorphin II)-induced antinociception in the warm water tail-flick test in rats. The oligonucleotides were administered in a 5-μl volume twice daily (intrathecal) (0800 and 1700 h) for 3 days. The day after the last injection, the rats were injected with [D-Ala²]deltorphin (60 μg, intrathecal) and tested in the warm water (52°C) tail-flick test for DOR-mediated antinociception. Data are presented as means ± SEM based on six to eight animals per group. The shaded area shows means ± SEM for deltorphin-treated controls. Student's t test was used for comparisons with deltorphin-treated controls, and all differences were considered as statistically significant at P < 0.05 (as indicated by the asterisk).