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 (P < 0.05). Furthermore, the plasma CGRP and SP levels in group D were much lower than that in group B and group C (P < 0.05), but there was no statistical difference between group B and group C (P > 0.05).
Conclusion: Heat coagulation of MMA may relieve symptoms of rats following nitroglycerin infusion, possibly by inhibiting the release of CGRP and SP.