Effect and mechanism of intraperitoneal injection of tetramethylpyrazine for the treatment of migraine in rats

BAI Fanghui; LI Hui; WU Zhiyong; GAO Yuan; NIE Linghui; CHEN Baotian

doi:10.3969/j.issn.1002-266X.2016.15.005

Abstract：Objective To explore the effect and mechanism of intraperitoneal injection of tetramethylpyrazine for the treatment of migraine in rats. Methods Thirty Sprague-Dawle ( SD) rats were randomly divided into three groups of 10 in each group:groups A, B and C. Rats in the group A were given intraperitoneal injection of ligustrazine hydrochloride injec-tion before modeling, groups B and C were given intraperitoneal injection of the same volume of normal saline for 7 days. Mi-graine rat model was established by subcutaneously injection of nitroglycerin after 30 min of the last delivery in the groups A and B, and group C with subcutaneous injection of 0. 5 mL normal saline. We observed the frequency of scratching head and climbing cage of each rat. The expression of transient receptor potential cation channel subfamily V member 1 (TRPV1) pro-tein in rat trigeminocervical complex ( TCC) was detected with Western blotting, and the expression of TRPV1 mRNA was de-tected by real-time fluorescence quantificative PCR. Results Compared with group B, the frequency of scratching head and climbing cage in each period was significantly decreased in the groups A and C ( except the frequency of scratching head be-tween groups A and B in the 0-30 min after molding, statistical difference was found, all P<0. 05). Different levels of posi-tive expression of TRPV1 receptors in TCC of each group were observed by immunofluorescence. Compared with groups A and C, the expression intensity was higher in the group B, there was no statistical difference between group A and B. Compared with group B, the protein and mRNA expression of TRPV1 in TCC of group A and C were significantly decreased ( all P<0. 01). Conclusion Intraperitoneal injection of tetramethylpyrazine on migraine rats has a certain therapeutic effect, and the mechanism may be related to the inhibition of TRPV1 expression in trigeminal sensory neurons.