title: Oral L-arginine modulates blood lactate and interleukin-6 after exercise in HIV-infected men.
abstract: The acute administration of L-arginine (L-arg), a nitric oxide (NO) precursor, reduces lactate (LAC) concentration after exercise in healthy individuals. Lower concentration of L-arg may enhance the action of some inflammatory cytokines in HIV-1 infected patients. We tested the hypothesis that acute L-arg administration may reduce post-exercise blood LAC and inflammatory cytokines levels in HIV-infected patients. 10 HIV-infected men performed 2 maximal incremental cardiopulmonary exercise tests, separated by one week. 30 min before each test, patients received oral placebo or 20 g of L-arg, in random order. Blood LAC, tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-10 (IL-10) were measured before and up to 60 min after exercise. L-arg administration had no significant effect on exercise performance. Compared to placebo, L-arg administration reduced maximal post-exercise blood LAC from 8.7±0.6 to 6.9±0.4 mmol.L-1 (p<0.05). L-arg administration had no significant effect on TNF-alpha or IL-10 concentrations, but increased post-exercise IL-6 (placebo=19±3pg.mL-1; L-arg=63±8 pg.mL-1; p<0.05). In HIV-1 infected men, acute administration of L-arg reduces post-exercise blood LAC and increases IL-6 levels, suggesting the activation of the L-arg-NO pathway, with possible anti-inflammatory consequences.
authors.affiliation: Cardiology Division, Hospita de Clinicas de Porto Alegre, Brazil.
authors.forename: G N
authors.initials: GN
authors.lastname: Alves
authors.affiliation: Exercise Pathophysiology Research Laboratory, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: A M V
authors.initials: AM
authors.lastname: Tavares
authors.affiliation: Exercise Pathophysiology Research Laboratory, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: P J C
authors.initials: PJ
authors.lastname: Vieira
authors.affiliation: Division of Internal Medicine, Hospital de Clínicas de Porto Alegre, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Sprinz
authors.affiliation: Cardiology Division, Hospita de Clinicas de Porto Alegre, Brazil.
authors.forename: J P
authors.initials: JP
authors.lastname: Ribeiro
mesh_terms: D000284:Administration, Oral; D023241:Antiretroviral Therapy, Highly Active; D001120:Arginine / Q000008:administration & dosage*; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology*; D015658:HIV Infections / Q000097:blood* / Q000188:drug therapy; D006439:Hemodynamics; D006801:Humans; D016753:Interleukin-10 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood*; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012119:Respiration; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D019344:Lactic Acid; D001120:Arginine