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 Mar;102(3):759-63. doi: 10.1111/j.1476-5381.1991.tb12246.x.


1. Intravenous (i.v.) administration of adenosine diphosphate (ADP), platelet activating factor (PAF) and thrombin induced a dose-related accumulation of 111indium-labelled platelets within the thoracic region of anaesthetized rabbits. 2. I.v. administration of the inhibitor of NO biosynthesis, L-NG-nitro arginine methyl ester (L-NAME; 10 mg kg-1) significantly potentiated the peak platelet accumulation induced by ADP, PAF and thrombin. Additionally L-NAME prolonged the disaggregation of platelets in comparison to D-NAME (10 mg kg-1). Such changes were reversible by the administration of L-arginine (900 mg kg-1). 3. I.v. administration of PAF induced a small accumulation of 111indium-labelled neutrophils within the pulmonary circulation which could be greatly potentiated by pretreatment of the animals with L-NAME. In contrast, thrombin administration did not cause significant accumulation of 11indium-labelled erythrocytes in the pulmonary circulation of anaesthetized rabbits. 4. Intracarotid (i.c.) administration of thrombin induced a marked accumulation of radiolabelled platelets within the cranial vasculature which was not potentiated by the prior administration of L-NAME (at either 10 mg kg-1 or 100 mg kg-1). 5. These results suggest that endogenous NO may regulate platelet and polymorphonuclear leukocyte activation within the pulmonary but not the cerebral circulation of rabbits.

MeSH terms

  • Adenosine Diphosphate / pharmacology
  • Animals
  • Arginine / analogs & derivatives
  • Arginine / pharmacology
  • Cerebrovascular Circulation
  • Male
  • NG-Nitroarginine Methyl Ester
  • Neutrophils / physiology*
  • Nitric Oxide / physiology*
  • Platelet Activating Factor / pharmacology
  • Platelet Activation*
  • Pulmonary Circulation*
  • Rabbits


  • Platelet Activating Factor
  • Nitric Oxide
  • Adenosine Diphosphate
  • Arginine
  • NG-Nitroarginine Methyl Ester