Fig. 5.

Blockade effects of intrathecal injection of the microglial inhibitor minocycline (a), IL-10 antibody (b), β-endorphin antiserum (c), and selective μ-opioid receptor CTAP (d) on spinal cinobufagin-induced mechanical antiallodynia in the rat model of bone cancer pain. Female bone cancer pain rats, approximately 3 weeks after cancer cell inoculation, received two intrathecal injections, and mechanical thresholds in both the contralateral and ipsilateral hindpaws were measured by using electric von Frey filaments. Minocycline was intrathecally injected 4 h prior to cinobufagin treatment, whereas the IL-10 antibody, β-endorphin antiserum, and CTAP were intrathecally given 30 min before cinobufagin injection. Withdrawal thresholds were measured in both the contralateral and ipsilateral hindpaws. The data are presented as means ± SEM (n = 6 per group). The asterisk denotes statistical significance (p < 0.05) compared to the vehicle control group, by repeated-measured two-way ANOVA followed by the post hoc Student–Newman–Keuls test