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Adenosine constricts the isolated and perfused monkey coronary artery
1Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan.
Heart and Vessels
|January 1, 1990
Summary
Adenosine constricts monkey coronary arteries, potentially via calcium influx and cyclooxygenase products. This vasoconstriction is blocked by indomethacin but not other tested agents, suggesting unique mechanisms in primates.
Area of Science:
- Cardiovascular Pharmacology
- Physiology
Background:
- Adenosine exhibits differential effects on coronary arteries across species.
- Understanding adenosine's role in primate coronary vasoconstriction is crucial for cardiovascular research.
Purpose of the Study:
- To investigate the mechanism of adenosine-induced vasoconstriction in isolated monkey coronary arteries.
- To determine the involvement of calcium influx, cyclooxygenase products, and specific receptor pathways.
Main Methods:
- Isolated and perfused monkey coronary arteries were used to assess adenosine's effects.
- Pharmacological agents including diltiazem, aminophylline, phentolamine, methysergide, and indomethacin were employed.
- Comparison with vasoconstriction induced by KCl and norepinephrine (NE) was performed.
Main Results:
- Adenosine induced vasoconstriction in 37 of 58 monkey coronary arteries, contrasting with vasodilation in dog arteries.
- Diltiazem significantly attenuated adenosine-induced vasoconstriction.
- Indomethacin completely prevented vasoconstriction, while aminophylline, phentolamine, and methysergide had no significant effect.
Conclusions:
- Adenosine likely constricts monkey coronary arteries by increasing smooth muscle cell membrane calcium influx.
- Cyclooxygenase products appear to play a role in adenosine-mediated vasoconstriction.
- Adenosine receptors may not be directly involved in this specific vasoconstrictive response in monkeys.