Specific inhibitory effects of the NO donor MAHMA/NONOate on human platelets.
Nitric oxide (NO) is a physiological inhibitor of platelet function and has vaso-dilating effects. Therefore, synthesized NO releasing agents are used e.g. in cardiovascular medicine. The aim of this study was to characterise specific effects of the short living agent MAHMA/NONOate, a NO donor of the diazeniumdiolate class, on human platelets. Whole blood was obtained from healthy volunteers. In washed human platelets, the MAHMA/NONOate induced phosphorylation of the vasodilator-stimulated phosphoprotein (VASP) and cyclic nucleotide production were studied by Western Blot and by enzyme immunoassay kits. Agonist induced aggregation was measured in platelet rich plasma. Paired Student׳s t-test was used for statistical analysis. MAHMA/NONOate significantly stimulated platelet VASP phosphorylation in a concentration dependent manner and increased intracellular cGMP, but not cAMP levels, transiently. ODQ, a specific inhibitor of the soluble guanylyl cyclase, completely prevented VASP phosphorylation induced by low MAHMA/NONOate concentrations (5nM-15nM). The effects of higher concentrations (30-200nM) were only partially inhibited by ODQ. MAHMA/NONOate reduced platelet aggregation induced by low doses of agonists (2µM ADP, 0.5µg/mL collagen, 5µM TRAP-6) in a concentration dependent manner. MAHMA/NONOate leads to a rapid and transient activation of platelet inhibitory systems, accompanied by decreased platelet aggregation induced by low dose agonists. At low MAHMA/NONOate concentrations, the effects are cGMP dependent and at higher concentrations additionally cGMP independent. The substance could be of interest for clinical situations requiring transient and subtotal inhibition of platelet function.
Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Strasse 6, D-97080 Wuerzburg, Germany. Electronic address: Kobsar_A@ukw.de.
Anna
A
Kobsar
Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Strasse 6, D-97080 Wuerzburg, Germany. Electronic address: sandra.simonis@gmail.com.
Sandra
S
Simonis
Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Strasse 6, D-97080 Wuerzburg, Germany. Electronic address: Klinker_E@ukw.de.
Erdwine
E
Klinker
Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Strasse 6, D-97080 Wuerzburg, Germany. Electronic address: Koessler_A@ukw.de.
Angela
A
Koessler
Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Strasse 6, D-97080 Wuerzburg, Germany. Electronic address: Kuhn_S1@ukw.de.
Sabine
S
Kuhn
Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Strasse 6, D-97080 Wuerzburg, Germany. Electronic address: Boeck_M@ukw.de.
Markus
M
Boeck
Institute of Transfusion Medicine and Haemotherapy, University of Wuerzburg, Oberduerrbacher Strasse 6, D-97080 Wuerzburg, Germany. Electronic address: Koessler_J@ukw.de.
Juergen
J
Koessler
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000378:metabolism; D003094:Collagen / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D006801:Humans; D006834:Hydrazines / Q000494:pharmacology*; D008840:Microfilament Proteins / Q000378:metabolism; D008875:Middle Aged; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D055815:Young Adult; D000098662:Vasodilator-Stimulated Phosphoprotein
C105785:1-hexanamine-6-(2-hydroxy-1-methyl-2-nitrosohydrazine)-N-methyl; D015815:Cell Adhesion Molecules; D006834:Hydrazines; D008840:Microfilament Proteins; D020030:Nitric Oxide Donors; D010446:Peptide Fragments; D010750:Phosphoproteins; C082835:thrombin receptor peptide (42-47); D000098662:Vasodilator-Stimulated Phosphoprotein; D000244:Adenosine Diphosphate; D003094:Collagen; D000242:Cyclic AMP; D006152:Cyclic GMP
Aggregation; Cyclic nucleotide; MAHMA/NONOate (PubChem CID: 188926); NO donor; Platelets