Characterization of 5-hydroxytryptamine receptors in human temporal arteries: comparison between migraine suffers and nonsufferers.

An increase in the sensitivity of temporal arteries to 5-hydroxytryptamine (5-HT) has repeatedly been suggested on indirect evidence as an essential component of a migraine attack. We examined the 5-HT reactivity of isolated human temporal arteries removed from migraine sufferers and from patients operated on because of cerebral disorders. 5-HT constricted these vessels in a concentration-dependent manner, the response being attenuated by 10-8 tp 10-6 M methysergide. There was no difference in reactivity to 5-HT or methysergide between vessels from the two patient groups. The pA2 value calculated for methysergide in controls was 7.8 +/- 0.1 and in migraine patients, 7.6 +/- 0.2, which closely agreed with data obtained graphically using Schild plots: 7.8 amd 7.7. respectively. No difference existed between the patient groups due to age or sex. Thus, clear evidence has been obtained demonstrating the presence of 5-HT receptors in human temporal arteries, although we could observe no difference in the character of the 5-HT receptors between migraine patients and controls.