[Effect of electroacupuncture of "Zhiyang" (GV9) and "Jizhong" (GV6) on expression of CGRP and NLRP3 in rats with spinal cord injury].

ABSTRACT

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Zhiyang" (GV9) and "Jizhong" (GV6) of the Governor Vessel on the expression of calcitonin gene related peptide (CGRP)and NOD-like receptor pyrin containing 3 (NLRP3) in the injured anterior horn (AH) of rats with spinal cord injury (SCI), so as to explore its mechanisms underlying improvement of SCI. METHODS: Thirty-six male SD rats were randomly divided into sham operation (sham) group, model group and EA group which were further randomly allocated to 7 day (d) and 14 d subgroups (n=6 per subgroup). The SCI model was established by clamping the exposed spinal cord with an aneurysm clip. Rats of the EA group received EA of GV6 and GV9 for 30 min, once daily for 7 and 14 days, respectively. The Basso, Beattie and Bresnahan (BBB) was used to assess changes of the locomotor function on the 1st, 3rd, 7th and 14th day after SCI. The protein expression levels of CGRP, NLRP3, apoptosis-associated speck-like protein (ASC) and cysteinyl aspartate specific protease-1 (caspase-1) in the anterior horn region of the spinal cord on the 7th and 14th after SCI were detected by Western blot. RESULTS: The BBB scores on the 1st, 3rd, 7th and 14th d after SCI were significantly lower in the model group than in the sham group (P<0.05), whereas the expression levels of NLRP3, ASC and caspase-1 proteins on day 7 and 14 were markedly higher in the model group than in the sham group (P<0.05, P<0.01). Compared with the model group, the BBB score and CGRP expression on the 7th and 14th d were significantly increased in the EA group (P<0.05,P<0.01), while the expression levels of NLRP3, ASC and caspase-1 were obviously decreased in the EA group (P<0.01). CONCLUSION: EA of GV6 and GV9 can improve the locomotion of SCI rats, which may be associated with its function in up-regulating the expression of CGRP and down-regulating the expression of NLRP3, ASC and caspase-1 proteins in the spinal anterior horn tissue.