title: L-arginine infusion decreases platelet aggregation through an intraplatelet nitric oxide release.
abstract: Nitric Oxide (NO) inhibits platelet aggregation via activation of an intraplatelet soluble guanylate cyclase which induces an increase in cyclic GMP (1). It has been also demonstrated that platelets contain a constitutive, calcium-dependent, NO synthase which is activated by collagen-induced platelet aggregation. This leads to a NO synthesis from L-Arginine (L-Arg), which in turn increases cyclic GMP and down-regulates platelet aggregation (2). In vitro administration of supraphysiological concentrations of L-Arg enhances platelet cyclic GMP levels by increasing NO production and reduces platelet aggregation. This effect is reversed by pre-incubation with NO-synthase inhibitors (3). These results indicate that the L-Arg: NO pathway plays an important role in the modulation of human platelet aggregation (4). In vivo L-Arg, when administered i.v., induces hypotension (5) and vasodilatation (6,7) in humans, and when orally supplemented reduces platelet aggregability both in hypercholesterolemic rabbits and healthy men (8,9).
authors.affiliation: Department of Medical Sciences, University of Modena, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Marietta
authors.forename: F
authors.initials: F
authors.lastname: Facchinetti
authors.forename: I
authors.initials: I
authors.lastname: Neri
authors.forename: F
authors.initials: F
authors.lastname: Piccinini
authors.forename: A
authors.initials: A
authors.lastname: Volpe
authors.forename: G
authors.initials: G
authors.lastname: Torelli
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D001120:Arginine / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002956:Citrulline / Q000097:blood / Q000187:drug effects; D003094:Collagen / Q000494:pharmacology; D003971:Diastole; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D009569:Nitric Oxide / Q000097:blood*; D009573:Nitrites / Q000097:blood; D010919:Placebos; D010974:Platelet Aggregation / Q000187:drug effects*; D013599:Systole; D013997:Time Factors
chemical_list: D009573:Nitrites; D010919:Placebos; D002956:Citrulline; D009569:Nitric Oxide; D000244:Adenosine Diphosphate; D003094:Collagen; D001120:Arginine