The lack of vasoconstrictor effect of the pineal hormone melatonin in an animal model predictive of antimigraine activity.
The pineal hormone, melatonin, has been implicated in the pathophysiology of migraine and several studies have demonstrated its vasoconstrictor properties. In the present study, systemic and carotid haemodynamic effects of melatonin, administered directly into the carotid artery, were investigated in anaesthetized pigs. Ten-minute intracarotid infusions of melatonin (1, 10 and 100 microg kg(-1) min(-1)) produced slight decreases in blood pressure and total carotid and arteriovenous anastomotic blood flows, but nutrient blood flow was not affected. The decrease in carotid blood flow was entirely caused by the hypotension, since no changes in vascular conductance values were observed. It is concluded that melatonin itself is not capable of producing vasoconstriction in the cranial circulation of anaesthetized pigs. Thus, it appears that melatonin has no anti-migraine potential via a vasoconstrictor mechanism.
Tom
B
B
Department of Pharmacology, Erasmus University Medical Centre Rotterdam, Rotterdam, The Netherlands.
De Vries
P
P
Heiligers
J P
JP
Willems
E W
EW
Scalbert
E
E
Delagrange
P
P
Saxena
P R
PR
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D002339:Carotid Arteries / Q000187:drug effects* / Q000503:physiopathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008550:Melatonin / Q000494:pharmacology* / Q000502:physiology / Q000627:therapeutic use; D008881:Migraine Disorders / Q000188:drug therapy / Q000503:physiopathology*; D010870:Pineal Gland / Q000503:physiopathology; D012039:Regional Blood Flow / Q000187:drug effects; D013552:Swine; D014661:Vasoconstriction / Q000187:drug effects*
D000975:Antioxidants; D008550:Melatonin