Role of spinal kinesin superfamily motor protein 17 in remifentanil-induced hyperalgesia in rats with incisional pain

Objective To evaluate the role of spinal kinesin superfamily motor protein 17(KIF17)in remifentanil-induced hyperalgesia in rats with incisional pain. Methods Forty male Sprague-Dawley rats, aged 2-3 months, weighing 240-260 g, were divided into 5 groups(n=8 each)using a random number table: control group(group C), remifentanil group(group R), incisional pain group(group I), remifentanil plus incisional pain group(group R+ I)and remifentanil plus incisional pain plus KIF17 inhibitor group(group R+ I+ M). Normal saline 1.5 ml was intravenously infused for 60 min in group C. Remifentanil 1 μg·kg-1·min-1 was intravenously infused for 60 min in group R. In group I, incisional pain model was established, and normal saline 1.5 ml was intravenously infused for 60 min at the same time.In group R+ I, incisional pain model was established, and remifentanil 1.5 ml was intravenously infused for 60 min at the same time.In group R+ I+ M, KIF17 inhibitor Myr-Rc-13 10 μg(in 10 μl dimethyl sulfoxide)was injected intrathecally, and remifentanil 1 μg·kg-1·min-1 was intravenously infused for 60 min while incisional pain model was established.The mechanical paw withdrawal threshold(MWT)and thermal paw withdrawal latency(TWL)were measured at 24 h before remifentanil or normal saline infusion and at 2, 6, 24 and 48 h after the end of infusion.The rats were sacrificed after the last measurement of pain threshold, and the lumbar segment of the spinal cord was removed for determination of the expression of KIF17 and phosphorylated KIF17(pKIF17)by Western blot. Results Compared with group C, MWT was significantly decreased, TWL was shortened, and the expression of KIF17 and pKIF17 was up-regulated in R, I and R+ I groups(P<0.05). Compared with R and I groups, MWT was significantly decreased, TWL was shortened, and the expression of KIF17 and pKIF17 was up-regulated in group R+ I(P<0.05). Compared with group I+ R, MWT was significantly increased, TWL was prolonged, and the expression of KIF17 and pKIF17 was down-regulated in group R+ I+ M(P<0.05). Conclusion Increased activity of KIF17 is involved in the development and maintenance of remifentanil-induced hyperalgesia in rats with incisional pain. Key words: Piperidines; Pain, postoperative; Hyperalgesia; Kinesin; Spinal cord