Effects of rizatriptan on calcitonin gene-related peptide, proenkephalin and cholecystokinin mRNA expressions in the trigeminal ganglia of a rat migraine model / 中华神经科杂志

ABSTRACT

Objective This study assesses the influence of rizatriptan on calcitonin gene-related peptide (CGRP),proenkephalin (PENK) and cholecystokinin (CCK) mRNA expressions in the trigeminal ganglia of a rat migraine model and investigates the possible mechanisms by which triptans treat migraine.Methods A total of 24 rats were randomly divided into four groupsnormal control group (A),migraine model group(B),rizatriptan control group (C) and rizatriptan treatment group(D).Groups C and D were intragastrically perfused with rizatriptan,1 mg/kg per day.After 7 days,nitroglycerin was subcutaneously injected into the buttocks of the groups B and D to induce migraine.Two hours after nitroglycerin injection,the trigeminal ganglia was isolated.CGRP,PENK and CCK mRNA expressions in the trigeminal ganglia were determined using SYBR Green Ⅰ real-time quantitative PCR.Results The copy number of CGRP mRNA (× 107) in 200 ng total RNA of each group was 0.05 ±0.01,1.30 ±0.52,0.23 ±0.12,0.43 ±0.33 ; The copy number of PENK mRNA (× 103) in 200 ng total RNA of each group was 3.30 ± 1.65,0.34 ±0.14,3.91 ± 2.44,0.71 ± 0.13.The copy number of CGRP mRNA in the trigeminal ganglia of group B was significantly higher than that of group A (q =7.854,P ＜ 0.05) ; CGRP mRNA expressions were significantly lower in the trigeminal ganglia of rats in group D compared with group B (q =5.458,P ＜0.05).Compared with group A,PENK mRNA expressions in the trigeminal ganglia of rats were significantly lower in group B (q =4.478,P ＜ 0.05).PENK mRNA expressions were significantly higher in trigeminal ganglia of rats in group C compared with group D (q =4.838,P ＜ 0.05).CCK mRNA expression in trigeminal ganglia of rats was similar among groups.Conelusions Rizatriptan can decrease the expressions of CGRP in the trigeminal ganglia of the migraine rats and exhibits neurogenic inflammation triggered by CGRP.PENK expressions decrease in the trigeminal ganglia of the migraine rats,weaken the analgesic effects of enkephalin.