-transparent.png){kind=logo}
Canine cerebral arterial strips denuded of endothelium responded to nicotine and transmural electrical stimulation with relaxations, which were abolished by NG-nitro-L-arginine and methylene blue. Magnitudes of relaxation did not differ in the arteries contracted with prostaglandin F2alpha and sumatriptan, an effective therapeutic of migraine. Sumatriptan concentration-dependently contracted the arteries responding to 2 Hz stimulation with persistent relaxations, and the concentration of this 5-HT1B/1D/1F receptor agonist to overcome the relaxation averaged 1.06 x 10(-7) M. Acetylcholine inhibited the response to nerve stimulation due possibly to its action on prejunctional nitroxidergic nerves; the inhibition did not differ in the arteries contracted with prostaglandin F2alpha and K+. It appears that sumatriptan does not interfere with the release of nitric oxide from nerves but counteracts the neurogenic relaxation by functional antagonistic action on smooth muscle. Prejunctional inhibition by muscarinic receptor activation is unlikely associated with opening of neuronal K+ channels.
K Ayajiki, and
H Fujioka, and
K Noda, and
T Okamura, and
N Toda
January 1999,
Journal of cardiovascular pharmacology,
K Ayajiki, and
H Fujioka, and
K Noda, and
T Okamura, and
N Toda
April 1994,
Cardiovascular research,
K Ayajiki, and
H Fujioka, and
K Noda, and
T Okamura, and
N Toda
May 1991,
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism,
K Ayajiki, and
H Fujioka, and
K Noda, and
T Okamura, and
N Toda
April 1997,
The American journal of physiology,
K Ayajiki, and
H Fujioka, and
K Noda, and
T Okamura, and
N Toda
July 1998,
Pflugers Archiv : European journal of physiology,
K Ayajiki, and
H Fujioka, and
K Noda, and
T Okamura, and
N Toda
August 1994,
Neuroscience letters,
K Ayajiki, and
H Fujioka, and
K Noda, and
T Okamura, and
N Toda
November 1993,
Brain research,
K Ayajiki, and
H Fujioka, and
K Noda, and
T Okamura, and
N Toda
April 1992,
The Journal of pharmacology and experimental therapeutics,
K Ayajiki, and
H Fujioka, and
K Noda, and
T Okamura, and
N Toda
June 1993,
Neuroscience,
K Ayajiki, and
H Fujioka, and
K Noda, and
T Okamura, and
N Toda
January 1997,
The Journal of physiology,
