Heat Coagulation of Middle Meningeal Artery Affects Plasma CGRP and Substance P Levels in Migraine Rat Triggered by Nitroglycerin

Objective:To detect the influence of heat coagulation of middle meningeal artery(MMA) on plasma CGRP and SP levels in migraine rat triggered by nitroglycerin(NTG).Method:Twenty-four female Wistar rats were randomly divided into four groups,with six rats in each group.In group A,rats were treated with isotonic saline;in group B,rats were injected subcutaneously with 10 mg/kg nitroglycerin to set up the animal model of migraine;in group C,rats were subjected to sham surgery by merely exposing MMA and then injected with nitroglycerin(10 mg/kg);and in group D,rats were firstly subjected to heat coagulation of MMA and,subsequently,injected with nitroglycerin(10 mg/kg).Following the injection,the animal's behavior was continuously recorded by an observer.Radioimmunoassay was employed to measure the amounts of CGRP and SP in venous plasma.Result:Injection of 10 mg/kg nitroglycerin was able to trigger the animal model of migraine as evidenced by the appearances of a series of symptoms,such as,scratching head frequently,climbing cage and red ear.Rats in group A occasionally showed off scratching head,whereas,rats from group B and group C presented with much severe symptoms.Of note,rats in group D appeared slightly scratching head and climbing cage,without red ear compared with group B and C.At the same time,the amounts of plasma CGRP and SP in group B,group C,or group D were increased significantly compared with that of group A(P0.05).Furthermore,the plasma CGRP and SP levels in group D were much lower than that in group B and group C(P0.05),but there was no statistical difference between group B and group C(P0.05).Conclusion:Heat coagulation of MMA may relieve symptoms of rats following nitroglycerin infusion,possibly by inhibiting the release of CGRP and SP.