Fig. 5

Analgesic effect of rDKK3 on mechanical allodynia in neuropathic pain rats. a, b A single dose of rDKK3 (30 and 50 μg) markedly increased the ipsilateral PWT in SNI rats, beginning at 2 h and lasted for at least 4 h, and didn’t affect the contralateral PWT (^***p < 0.001, ^****p < 0.0001 compared with SNI + Vehicle group, n = 6 in each group). c, d Repetitive injections of rDKK3 (30 μg, i.t.) considerably reversed established mechanical allodynia in the ipsilateral side of SNI rats, and didn’t affect the contralateral PWT (^****p < 0.0001 compared with Sham + Vehicle group, ^#p < 0.05, ^##p < 0.01 compared with SNI + Vehicle group, n = 6 in each group). e, f The ipsilateral PWT was significantly increased from day 3 to day 8 in rDKK3-treated SNI rats compared with vehicle-treated SNI rats (^****p < 0.0001 compared with Sham + Vehicle group, ^#p < 0.05, ^##p < 0.01 compared with SNI + Vehicle group, n = 6 in each group). And the contralateral PWT in sham and SNI rats treated with Vehicle or rDKK3 had no significant change during the observation period (p > 0.05). g Horizontal movement traces in the OFT of sham and SNI rats treated with Vehicle or rDKK3. h, i The OFT result showed that there was no significant difference in the total distance and average speed between the Sham + Vehicle group, Sham + rDKK3 group, SNI + Vehicle group, and SNI + rDKK3 group (p > 0.05)