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Coronary vasoconstrictor effects of atriopeptin II.
Science (New York, N.Y.)
|November 1, 1985
Summary
Atrial natriuretic peptides, like atriopeptin II, act as potent coronary vasoconstrictors. This effect requires the peptide's disulfide bridge for activity.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Pharmacology
Background:
- Atrial natriuretic peptides (ANPs) are known to reduce arterial pressure, cardiac filling pressure, and cardiac output.
- The specific role of ANPs in coronary circulation has not been fully elucidated.
Purpose of the Study:
- To investigate the effect of atriopeptin II, a specific ANP, on coronary blood flow.
- To determine the dose-response relationship and structural requirements for the coronary vasoconstrictor activity of atriopeptin II.
Main Methods:
- Utilizing isolated, Langendorff-perfused guinea pig, rat, and dog hearts.
- Administering varying concentrations of atriopeptin II to assess coronary vasoconstriction.
- Investigating the role of the disulfide bridge by reducing it and observing the effect on vasoconstrictor activity.
Main Results:
- Atriopeptin II demonstrated potent coronary vasoconstrictor activity in guinea pig hearts, with a median effective dose of 26 nanomoles.
- Coronary flow was significantly reduced at higher doses, nearly ceasing at 100 nanomoles.
- Similar vasoconstrictor effects were observed in rat and dog heart preparations.
- Reduction of the disulfide bridge abolished the vasoconstrictor activity.
Conclusions:
- Atriopeptin II is a potent coronary vasoconstrictor in mammalian hearts.
- The disulfide bridge within the atriopeptin II molecule is essential for its vasoconstrictor function.
- These findings suggest a complex role for ANPs in regulating coronary hemodynamics.
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