Figure 4. TACAN AS-ODN attenuates LPS-induced mechanical hyperalgesia.

TACAN AS- (120 μg/20 μL) or MM- (120 μg/20 μL) ODN was administered intrathecally in rats, once a day, for three consecutive days. On the fourth day, approximately 24 h after the last intrathecal administration of AS-ODN, when the mechanical nociceptive threshold was significantly elevated from pre-ODN baseline in the TACAN AS-ODN-treated group (t₍₅₎=1.291; p=0.2532, for the TACAN MM-ODN-treated group and, t₍₅₎=5.534; ^##p=0.0026, for the TACAN AS-ODN-treated group, when the mechanical nociceptive threshold is compared before and approximately 24 hours after the third intrathecal injection of ODNs; paired Student’s t-test), LPS (100 μg/kg) was injected intraperitoneally (i.p.). The mechanical nociceptive threshold was evaluated 1 h and 1, 2, 5 and 8 days after LPS. In the group that received TACAN AS-ODN, mechanical hyperalgesia induced by systemic LPS was robustly attenuated 1 hour after its i.p. administration, and still attenuated a 1, 2, and 5 days later, compared with the TACAN MM-ODN-treated group (F_(6,60)=21.25; ***p<0.0009, when the TACAN AS-ODN- is compared with the TACAN MM-ODN-treated group before intraperitoneal LPS; ****p<0.0001 1 h and 1 and 2 day after intraperitoneal LPS: **p=0.0020; 5 days after intraperitoneal LPS; when the TACAN AS-ODN- is compared with TACAN MM-ODN-treated group; two-way repeated-measures ANOVA followed by Bonferroni’s multiple comparison test). Eight days after i.p. LPS there was no difference between the TACAN AS- and MM-ODN-treated groups. n=6 per group.