title: Oral L-arginine administration does not inhibit thrombosis on an experimental model of arterial thrombosis: the effect on the apyrasic activity of the arterial wall.
abstract: Despite the extensive research on the pharmacology of L-arginine, there are only few data on its antithrombotic properties. We studied the effect of oral L-arginine administration in a model of arterial thrombosis in rabbits divided into three groups: group 1, group without intervention; group 2, control group, treated with normal diet and submitted to the thrombosis-triggering protocol; group 3, treated for 2 weeks with L-arginine (2.25%) prior the protocol. L-Arginine did not alter platelet aggregation nor coagulation parameters but reduced vascular activities of both ADPase (49.1 +/- 8.5 versus 28.9 +/- 8.3 versus 18.8 +/- 10.3 nmoles inorganic phosphate/min per mg protein; mean +/- SD; group 1 versus group 2 versus group 3, respectively; ANOVA F = 19.21; P < 0.0001) and ATPase (97.8 +/- 15.8 versus 52.1 +/- 11.6 versus 31.9 +/- 16.3 nmoles inorganic phosphate/min per mg protein; mean +/- SD; group 1 versus group 2 versus group 3, respectively; ANOVA, F = 34.65; P < 0.0001). L-Arginine did not reduce the thrombi area (17.1 mm, 9.02 and 48.07, versus 27.04 mm, 25.4 and 70.39, median, percentile 25 and 75 respectively, P = 0.079; group 2 versus group 3, respectively). In conclusion, oral L-arginine administration did not inhibit thrombosis, and, conversely, it significantly reduced the arterial wall ADPase and ATPase activities. This effect may limit its antithrombotic properties.
authors.affiliation: Department of Internal Medicine and Cardiology, Federal University Hospital of Rio Grande do Sul (HCPA), Brazil.
authors.forename: Germán R
authors.initials: GR
authors.lastname: Iturry-Yamamoto
authors.forename: Ana M O
authors.initials: AM
authors.lastname: Battastini
authors.forename: Norberto L C
authors.initials: NL
authors.lastname: Martins
authors.forename: Maria I
authors.initials: MI
authors.lastname: Edelweiss
authors.forename: João J F
authors.initials: JJ
authors.lastname: Sarkis
authors.forename: Jorge P
authors.initials: JP
authors.lastname: Ribeiro
authors.forename: Paulo D
authors.initials: PD
authors.lastname: Picon
mesh_terms: D000251:Adenosine Triphosphatases / Q000187:drug effects* / Q000378:metabolism; D000284:Administration, Oral; D000704:Analysis of Variance; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000201:enzymology; D001081:Apyrase / Q000187:drug effects* / Q000378:metabolism; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology*; D001777:Blood Coagulation / Q000187:drug effects; D016009:Chi-Square Distribution; D005263:Femoral Artery / Q000187:drug effects / Q000201:enzymology; D008297:Male; D023421:Models, Animal; D010974:Platelet Aggregation / Q000187:drug effects*; D011817:Rabbits; D018709:Statistics, Nonparametric; D013927:Thrombosis / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*
chemical_list: D001120:Arginine; D000251:Adenosine Triphosphatases; D001081:Apyrase