Haemodynamic effects of intravenous human calcitonin-gene-related peptide in man.

1. The effects of intravenous bolus doses of human calcitonin-gene-related peptide (hCGRP) were studied in ten healthy male volunteers. 2.5, 10 and 25 micrograms of hCGRP and placebo were administered to each subject in a randomized double-blind study. 2. hCGRP had no effect on systolic or diastolic blood pressure in the supine or standing position. 3. hCGRP increased supine and standing heart rate. Both the extent and duration of the tachycardia were dose related. 4. Plasma noradrenaline levels were transiently increased after 10 and 25 micrograms of hCGRP. 5. All subjects displayed marked facial flushing after the two higher doses of hCGRP. 6. We conclude that systemic administration of hCGRP produces tachycardia and stimulation of the sympathetic nervous system in the absence of any change in blood pressure.