Thromb Haemost 1999; 81(06): 961-966
DOI: 10.1055/s-0037-1614607
Letters to the Editor
Schattauer GmbH

Endogenous Nitric Oxide Acts as a Natural Antithrombotic Agent In Vivo by Inhibiting Platelet Aggregation in the Pulmonary Vasculature

Michael Emerson
,
Stefania Momi
1   From the Sackler Institute of Pulmonary Pharmacology, King’s College London, London, UK; Institute of Internal and Vascular Medicine, University of Perugia, Perugia, Italy
,
William Paul
,
Paolo Alberti Francesco
2   Institute of Pathology, University of Perugia, Perugia, Italy
,
Clive Page
,
Paolo Gresele
1   From the Sackler Institute of Pulmonary Pharmacology, King’s College London, London, UK; Institute of Internal and Vascular Medicine, University of Perugia, Perugia, Italy
› Author Affiliations
Further Information

Publication History

Received 14 September 1998

Accepted after revision 15 February 1999

Publication Date:
09 December 2017 (online)

Summary

Nitric oxide (NO) is a powerful vasodilator and an inhibitor of platelet aggregation in vitro. While the ability of NO to modulate vascular tone in vivo has been proven, only a few studies have assessed its platelet inhibitory activity in vivo.

We have employed two complementary animal models of pulmonary platelet thromboembolism to assess the antithrombotic activity of endogenous NO in vivo. The inhibition of nitric oxide synthase (NOS) by L-NAME significantly potentiated while the administration of the NOS substrate L-arginine significantly reduced the accumulation of 111In-labelled platelets in the pulmonary vasculature of rabbits induced by intravenous collagen plus epinephrine. L-NAME or L-arginine did not, however, modify 111In-labelled erythrocyte distribution in lungs and phenylephrine had no effect on platelet accumulation following collagen + adrenaline, suggesting that the effects of L-NAME were not due to vasoconstriction but rather to a direct modification of platelet function. In mice, L-NAME significantly reduced the dose of collagen + adrenaline required to induce thromboembolic mortality, increased the fall in circulating platelets and increased the % of pulmonary vessels occluded by platelet thrombi. The effects of L-NAME were reversed by L-arginine but not by a dose of nicardipine exerting maximal vasodilatation. Phenylephrine did not potentiate collagen + adrenaline-induced mortality.

In the pulmonary vasculature in vivo, endogenous NO inhibits collagen + adrenaline-induced aggregation and enhances platelet disaggregation. This natural modulator function of NO is exerted via a direct effect on platelets and not as a result of haemodynamic changes.

 
  • References

  • 1 Furchgott RF. The role of endothelium in the responses of vascular smooth muscle to drugs. Annu Rev Pharmacol Toxicol 1984; 214: 175-97.
  • 2 Bassenge E. Endothelium-mediated regulation of coronary tone. Basic Res Cardiol 1990; 86 (Suppl. 02) (Suppl) 69-76.
  • 3 Palmer RMJ, Ferrige AG, Moncada S. Nitric oxide release accounts for the biological activity of endothelium-derived relaxing factor. Nature 1986; 327: 524-6.
  • 4 Radomski MW, Palmer RM, Moncada S. Comparative pharmacology of endothelium-derived relaxing factor, nitric oxide and prostacyclin in platelets. Br J Pharmacol 1987; 92: 181-7.
  • 5 Radomski MW, Palmer RMJ, Moncada S. Endogenous nitric oxide inhibits human platelet adhesion to vascular endothelium. Lancet 1987; ii: 1057-8.
  • 6 Hogan JC, Lewis MJ, Henderson AH. In vivo EDRF activity influences platelet function. Br J Pharmacol 1988; 94: 1020-2.
  • 7 Golino P, Capelli-Bigazzi M, Ambrosio G, Ragini M, Russolillo E, Condorelli M, Chiariello M. Endothelium-derived relaxing factor modulates platelet aggregation in an in vivo model of recurrent platelet activation. Circ Res 1992; 71: 1447-56.
  • 8 Golino P, Ashton JH, Buja LM, Taylor AL, McNatt J, Rosolowsky M, Campbell WB, Willerson JT. Local platelet activation causes vasoconstriction of large epicardial canine coronary arteries in vivo: Thromboxane A2 and serotonin are possible mediators. Circulation 1991; 79: 154-66.
  • 9 Golino P, Buja LM, Yao SK, McNatt J, Willerson JT. Failure of nitroglycerin and diltiazem to reduce platelet-mediated vasoconstriction in dogs with coronary artery stenosis and endothelial injury: Further evidence for thromboxane A2 and serotonin as mediators of coronary artery vasoconstriction in vivo. . J Am Coll Cardiol 1992; 15: 718-26.
  • 10 Simon DI, Stamler JS, Loh E, Loscalzo J, Francis SA, Creager MA. Effect of nitric oxide synthase inhibition on bleeding time in humans. J Cardiovasc Pharmacol 1995; 26: 339-42.
  • 11 Yao SK, Ober JC, Krishnaswami A, Ferguson JJ, Anderson JJ, Anderson HV, Golino P, Buja LM, Willerson JT. Endogenous nitric oxide protects against platelet aggregation and cyclic flow variations in stenosed and endothelium-injured arteries. Circulation 1992; 86: 1302-9.
  • 12 Hogman M, Frostell C, Arnberg H, Sandhagen B, Hedenstierna G. Prolonged bleeding time during nitric oxide inhalation in the rabbit. Acta Physiol Scand 1994; 151: 125-9.
  • 13 Molnar M, Suto T, Toth T, Hertetendy F. Prolonged blockade of nitric oxide synthesis in gravid rats produces sustained hypertension, proteinuria, thrombocytopenia and intrauterine growth retardation. Am J Obstet Gynecol 1994; 170: 1458-66.
  • 14 May GR, Crook P, Moore PK, Page CP. The role of nitric oxide as an endogenous regulator of platelet and neutrophil activation within the pulmonary circulation of the rabbit. Br J Pharmacol 1991; 102: 759-63.
  • 15 Lidbury PS, Korbut R, Vane JR. Sodium nitroprusside modulates the fibrinolytic system in the rabbit. Br J Pharmacol 1990; 101: 527-30.
  • 16 Kawabata A. Evidence that endogenous nitric oxide modulates plasma fibrinogen levels in the rat. Br J Pharmacol 1996; 117: 236-7.
  • 17 Ward E, Angus JA. Acute and chronic inhibition of nitric oxide synthase in conscious rabbits: Role of nitric oxide in the control of vascular tone. J Cardiovasc Pharmacol 1993; 21: 804-14.
  • 18 Paul W, Gresele P, Momi S, Bianchi G, Page CP. The effect of defibrotide on thromboembolism in the pulmonary vasculature of mice and in the cerebral vasculature of rabbits. Br J Pharmacol 1993; 110: 1565-71.
  • 19 Gresele P, Momi S, Berrettini M, Nenci GG, Schwarz HP, Semeraro N, Colucci M. Activated human protein C prevents thrombin-induced thromboembolism in mice. Evidence suggesting that activated protein C promotes the removal of intravascular fibrin through the inhibition of additional thrombin generation. J Clin Invest 1998; 101: 667-76.
  • 20 Huang E, Detwiler TC. Characteristics of the synergistic actions of platelet agonists. Blood 1981; 54: 685-91.
  • 21 May GR, Herd CM, Butler KD, Page CP. Radioisotopic model for investigating thromboembolism in the rabbit. J Pharmacol Methods 1990; 24: 19-35.
  • 22 Gresele P, Corona C, Persia C, Berrettini M, Nenci GG. Platelet lung thromboembolism after intravenous (i.v.) collagen plus epinephrine (coll+epi) in mice: Characterisation of the model. Fibrinolysis 1991; 4 S (01) 91
  • 23 Honey AC, Lad N, Tuffin DP. Effect of indomethacin and dazoxiben on intravascular platelet aggregation in the anaesthetised rabbit. Thromb Haemost 1986; 56: 80-5.
  • 24 Page CP, Paul W, Morley J. An in vivo model for studying platelet aggregation and disaggregation. Thromb Haemost 1982; 47: 210-3.
  • 25 Di Minno G, Silver JM. Mouse antithrombotic assay: A simple method for the evaluation of antithrombotic agents in vivo. Potentiation of anti-thrombotic activity by ethanol alcohol. J Pharmacol Exp Ther 1983; 225: 57-60.
  • 26 Gresele P, Corona C, Alberti P, Nenci GG. Picotamide protects mice from death in a pulmonary embolism model by a mechanism independent from thromboxane suppression. Thromb Haemost 1990; 64: 80-6.
  • 27 Brecher G, Cronkite EP. Morphology and enumeration of human blood platelets. J Appl Physiol 1950; 3: 365-75.
  • 28 Molinari A, Guarneri L, Pacei E, de Marchi F, Cerletti C, de Gaetano G. Mouse antithrombotic assay: The effects of Ca++channel blockers are platelet independent. J Pharmacol Exp Ther 1987; 240: 623-7.
  • 29 Du Z-Y, Woodman DL. The effect of hypercholesterolaemia and atherosclerosis on α-adrenoceptor-mediated vasoconstriction in conscious rabbits and rabbit aorta. Eur J Pharmacol 1992; 211: 149-56.
  • 30 Diodati JG, Dakak N, Gilligan DM, Quyyumi AA. Effect of atherosclerosis on endothelium-dependent inhibition of platelet activation in humans. Circulation 1998; 98: 17-24.
  • 31 Williams MW, Taft CS, Ramnauth S, Zhao ZQ, Vinten-Johansen J. Endogenous nitric oxide (NO) protects against ischaemia-reperfusion injury in the rabbit. Cardiovasc Res 1995; 30: 79-86.