Calcitonin gene-related peptide (CGRP) levels during glyceryl trinitrate (GTN)-induced headache in healthy volunteers

Abstract

The role of nitric oxide (NO) in migraine has been studied in the experimental glyceryl trinitrate (GTN)-infusion headache model. We hypothesized that GTN-induced headache may activate the trigeminovascular system and be associated with increased levels of sensory neuropeptides, including calcitonin gene-related peptide (CGRP). CGRP, vasoactive intestinal peptide (VIP), neuropeptide Y (NPY) and somatostatin plasma levels were measured before and after placebo/sumatriptan injection and during GTN-induced headache. Following a double-blind randomized cross-over design, 10 healthy volunteers received subcutaneous sumatriptan 6 mg or placebo. This was succeeded by 20 min of GTN (0.12 μg kg-1min-1) infusion. At baseline no subject reported headache (using verbal rating scale from 0 to 10) and the jugular CGRP-like immunoreactivity (-LI) level was 18.6 ±2.5 pmol/l. After a 20-min intravenous infusion of GTN 0.12μg kg-1min-1, median peak headache intensity was 4 (range 2-6) (P<0.05), while jugular CGRP-LI levels were unchanged (19.0 ±2.8 pmol/l; P>0.05). There were no changes in VIP-, NPY-or somatostatin-LI. In conclusion, the NO donor GTN appears not to induce headache via immediate CGRP release. © International Headache Society 2010.