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Adrenomedullin Does Not Inhibit Human Platelet Aggregation
1Departments of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, USA
Journal of Cardiovascular Pharmacology and Therapeutics
|February 23, 2000
Summary
Adrenomedullin (ADM) does not inhibit human platelet aggregation, despite increasing cyclic adenosine monophosphate (cAMP) levels. This suggests human platelets lack a functional ADM receptor linked to adenylate cyclase.
Area of Science:
- Biochemistry
- Cardiovascular Physiology
Background:
- Adrenomedullin (ADM), a hypotensive peptide, elevates cyclic adenosine monophosphate (cAMP) levels.
- Elevating cAMP typically inhibits platelet aggregation.
Purpose of the Study:
- To investigate the effect of ADM on human platelet aggregation.
- To determine if ADM influences adenosine 5'-diphosphate (ADP)-induced platelet aggregation.
Main Methods:
- Human platelet-rich plasma was incubated with varying concentrations of ADM.
- Platelet aggregation was measured following stimulation with adenosine 5'-diphosphate (ADP).
- Prostaglandin E1 (PGE1) was used as a positive control for inhibition.
Main Results:
- ADM did not alter adenosine 5'-diphosphate (ADP)-induced human platelet aggregation.
- Prostaglandin E1 (PGE1) effectively inhibited ADP-induced platelet aggregation.
- ADM induced a dose-dependent response in human chorionic artery rings.
Conclusions:
- Human platelets appear to lack a functional Adrenomedullin (ADM) receptor coupled to adenylate cyclase.
- ADM's hypotensive effects may not be mediated through direct platelet inhibition via cAMP in humans.
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