Prolonged exposure to oxyhemoglobin modifies the response of isolated dog middle cerebral arteries to vasoactive substances

16Citations
Citations of this article
14Readers
Mendeley users who have this article in their library.

Abstract

We exposed helical strips of dog middle cerebral arteries to oxyhemoglobin for 5 hours, rinsed them with bathing medium, and stored them overnight; we compared the responses of strips thus treated with the responses of strips without oxyhemoglobin treatment. Relaxation induced by nicotine was abolished by hexamethonium and was markedly inhibited after exposure to oxyhemoglobin. A low concentration of KCI (5 mM) elicited relaxation that was abolished by ouabain and significantly reduced by oxyhemoglobin. Endothelium-dependent relaxation caused by calcium ionophore A23187 was attenuated, and that caused by substance P was reversed to contraction after exposure to oxyhemoglobin. Contraction elicited by substance P also depended on endothelium and was abolished by indomethacin. Relaxation induced by TRK-100, a stable analogue of prostaglandin I2, was moderately attenuated by oxyhemoglobin. On the other hand, concentration-dependent relaxation induced by papaverine and contractile responses to KCI, serotonin, and prostaglandin F2a were not affected by oxyhemoglobin. Our results indicate that vasodilations mediated by vasodilator nerves, the electrogenic sodium pump, endothelium-derived relaxing factor, and prostaglandin I2 were impaired in dog cerebral arteries exposed to oxyhemoglobin. After exposure to oxyhemoglobin, vascular endothelium appears to participate in cerebroarterial contraction via a release of vasoconstrictor prostaglandins. These actions of oxyhemoglobin may be involved in the genesis of cerebral vasospasm after subarachnoid hemorrhage. © 1989 American Heart Association, Inc.

Cite

CITATION STYLE

APA

Onoue, H., Nakamura, N., & Toda, N. (1989). Prolonged exposure to oxyhemoglobin modifies the response of isolated dog middle cerebral arteries to vasoactive substances. Stroke, 20(5), 657–663. https://doi.org/10.1161/01.STR.20.5.657

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free