Objective:To observe the changes of endothelium(ET),cyclic adenosine monophosphate(cAMP)and cyclic guanosine monophosphate(cGMP)of plasma in patients with migraine during attack and headache-free interval,and to explore the effects of the changes in the outbreak of migraine.Methods:Radioimmuno-assay was used to measure the levels of plasma ET,cAMP and cGMP in80patients with migraine and30healthy controls.Results:The levels of ET and cAMP were remarkedly increased,but the level of cGMP in plasma was remarkedly reduced in the migraine group during attack than those in the control group and the migraine group during headache-free interval.Conclusion:The level changes of plasma ET,cAMP and cGMP during attack might be related to the outbreak of acute migraine.