Potentiating effects of extraluminal oxyhemoglobin to intraluminal 5-hydroxytryptamine in isolated canine internal carotid arteries.
The interaction between oxyhemoglobin (oxyHb) and 5-hydroxytryptamine (5-HT) was investigated in an experimental model of isolated canine internal and common carotid arteries with insertion of stainless steel cannulae. Extraluminal application of 10(-5) M oxyHb induced marked and long-lasting vasoconstriction in the internal carotid but not in the common carotid arteries. The 5-HT-induced vasoconstriction was potentiated significantly in both the internal and common carotid arteries. These potentiations were not influenced by the presence or absence of endothelium, a finding which was confirmed by vascular responses to intraluminal acetylcholine. It is concluded that the interaction between extraluminal oxyHb and intraluminal 5-HT may be one of the possible etiological factors behind the chronic phase of vascular spasm following subarachnoid hemorrhage.
Tanaka
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Y
Department of Neurosurgery and Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan.
Chiba
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S
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002343:Carotid Artery, Internal / Q000187:drug effects / Q000378:metabolism*; D004285:Dogs; D004357:Drug Synergism; D005260:Female; D002546:Ischemic Attack, Transient / Q000378:metabolism; D008297:Male; D010108:Oxyhemoglobins / Q000378:metabolism*; D012503:Saponins / Q000494:pharmacology; D012701:Serotonin / Q000378:metabolism* / Q000494:pharmacology; D013345:Subarachnoid Hemorrhage / Q000378:metabolism; D014661:Vasoconstriction / Q000187:drug effects
D010108:Oxyhemoglobins; D012503:Saponins; D012701:Serotonin