Sensory neuropeptides (substance P, calcitonin gene-related peptide) and vasoactive intestinal polypeptide in human saliva: their pattern in migraine and cluster headache.

Substance P, calcitonin gene-related peptide and vasoactive intestinal polypeptide-like immunoreactivities have been evaluated in the saliva of 15 subjects suffering from migraine without aura and 16 control subjects. All three peptides were also measured in the symptomatic/non-symptomatic side saliva sampled from 10 cluster headache sufferers during the cluster period, 5 cluster headache sufferers out of the cluster period, as well as in the right and left side saliva of 18 control subjects. The most interesting result gives a clear difference in common migraine and cluster headache salivary vasoactive intestinal polypeptide-like immunoreactivity contents. In fact, these are enhanced during cluster headache attack and decreased during migraine attack when compared with the interictal period vasoactive intestinal polypeptide-like immunoreactivity levels. Another remarkable finding concerns the significant increase of substance P-like immunoreactivity and calcitonin gene-related peptide-like immunoreactivity levels, from basal values, in the saliva sampled during both migraine and cluster headache attacks. Control subjects showed a calcitonin gene-related peptide-like immunoreactivity and substance P-like immunoreactivity salivary contents significantly higher than migraine sufferers' saliva sampled in basal conditions. Conversely, calcitonin gene-related peptide-like immunoreactivities levels in controls were lower than in cluster headache sufferers' saliva obtained during intervals. Finally, during cluster headache attacks the enhancement of substance P-like immunoreactivity and vasoactive intestinal polypeptide-like immunoreactivity salivary contents interest the non-symptomatic side, whereas the symptomatic side salivary substance P-like immunoreactivity and vasoactive intestinal polypeptide-like immunoreactivity contents remain unchanged. These findings do not allow any final conclusion. However, this biochemical evaluation indicates relevant changes of the salivary neuropeptides in diseases, such as migraine and cluster headache, in which pain transmission is surely involved.