What intracranial tissues in humans contain sumatriptan-sensitive serotonin 5-HT1-type receptors?
We investigated the presence of sumatriptan-sensitive serotonin (5-HT)1 receptors in different human tissues by using a radioligand-binding technique with [3H]5-HT. Sumatriptan displaced [3H]5-HT from frontal cortical and striatal membranes in a biphasic manner, with a high-affinity site corresponding to binding to the 5-HT1D receptor. In blood platelet membranes, sumatriptan displaced [3H]5-HT with a 100-fold lower affinity. Sumatriptan failed to displace [3H]5-HT in membranes from large cerebral arteries, pial vessels, coronary arteries and dura mater. These findings suggest that either there are no sumatriptan-sensitive 5-HT1 receptors on intracranial blood vessels or they are so small in number that they cannot be detected by the radioligand-binding technique. Other mechanisms, possibly centrally mediated, may be responsible for the antimigraine action of sumatriptan.
De Keyser
J
J
Department of Neurology, Vrije Universiteit Brussel, Belgium.
Vauquelin
G
G
De Backer
J P
JP
De Vos
H
H
Wilczak
N
N
D000328:Adult; D000368:Aged; D001552:Benzazepines / Q000494:pharmacology; D001667:Binding, Competitive / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects*; D002536:Cerebral Arteries / Q000187:drug effects; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D011869:Radioligand Assay; D011985:Receptors, Serotonin / Q000187:drug effects*; D018170:Sumatriptan / Q000494:pharmacology*
D001552:Benzazepines; D011985:Receptors, Serotonin; D018170:Sumatriptan