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Endothelin is a potent long-lasting vasoconstrictor in men
J G Clarke1, N Benjamin, S W Larkin
1Division of Cardiovascular Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London, United Kingdom.
The American Journal of Physiology
|December 1, 1989
Summary
Endothelin, a peptide regulating blood vessels, causes prolonged constriction in humans. Its effects on vascular tone suggest a role in long-term blood pressure management.
Area of Science:
- Cardiovascular Physiology
- Endocrinology
- Pharmacology
Background:
- Endothelin is a potent vasoconstrictor peptide identified in endothelial cells.
- Its effects on human peripheral circulation were previously uncharacterized.
Purpose of the Study:
- To investigate the effects of endothelin on human resistance and capacitance vessels.
- To determine the onset, duration, and potential antagonism of endothelin-induced vascular effects.
Main Methods:
- Local infusion of endothelin into forearm and dorsal hand veins of normal volunteers.
- Measurement of forearm blood flow and venous constriction.
- Co-infusion studies with nicardipine to assess antagonism.
Main Results:
- Endothelin infusion (5 pmol/min) reduced forearm blood flow by 39%, with a slow onset (55 min) and long duration (120 min).
- Nicardipine partially reversed endothelin-induced flow reduction, suggesting non-specific antagonism.
- Nicardipine did not reverse endothelin-induced dorsal hand vein constriction.
Conclusions:
- Endothelin exhibits a slow onset and prolonged action on human peripheral vasculature.
- These findings suggest endothelin's potential role in the long-term regulation of vascular tone and blood pressure.