Sumatriptan inhibits the release of CGRP and substance P from the rat spinal cord.
The possible presynaptic action of the anti-migraine drug sumatriptan on primary afferent fibres containing substance P and/or calcitonin gene-related peptide was investigated on superfused rat horizontal spinal cord slices with attached dorsal roots. Electrical stimulation of dorsal roots triggered a significant overflow of both peptides; this could be reduced by sumatriptan in a concentration-dependent manner. As expected from the involvement of 5-HT1B/1.D beta receptors, methiothepin, (-)tertatolol and GR 127,935, but not WAY 100,635, prevented the inhibitors effect of sumatriptan. These data support the idea that the anti-migraine action of sumatriptan may involve, at least in part, a presynaptic inhibitory control of nociceptive (trigeminovascular) substance P- and/or calcitonin gene-related peptide-containing sensory fibres.
INSERM U 288, Faculté de Médecine Pitié-Salptrière, Paris, France.
L
L
Arvieu
A
A
Mauborgne
S
S
Bourgoin
C
C
Oliver
P
P
Feltz
M
M
Hamon
F
F
Cesselin
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000187:drug effects*; D013373:Substance P / Q000187:drug effects*; D018170:Sumatriptan / Q000494:pharmacology*
D013373:Substance P; D018170:Sumatriptan; D015740:Calcitonin Gene-Related Peptide