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PLASMA SULFURED AMINO ACID RESPONSES TO METHIONINE‐LOADING TEST IN HIV+ PATIENTS
Author(s) -
Burini Roberto,
BorgesSantos Maria D,
Moreto Fernando,
Pereira Paulo,
MingYu Yong
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.742.7
Subject(s) - methionine , glutathione , glutamine , chemistry , amino acid , human immunodeficiency virus (hiv) , medicine , plasma concentration , cysteine , homocysteine , acetylcysteine , endocrinology , biochemistry , antioxidant , immunology , enzyme
HIV+ patients present low plasma levels of GSH which could be normalized through dietary supplements with either N‐acetylcysteine (NAC) or glutamine (Gln). Nevertheless, normal Cys levels were not obtained in such situations and lower trans‐sulfuration pathway activity could be the cause. It has been referred that after a methionine load (MetLo) mostly of Cys comes from trans‐sulfuration pathway. The study aimed to investigate the responses of Cys to the MetLo in healthy control (Co) and HIV+ dietary‐supplemented (NAC) subjects. The MetLo (0.1g Met/kg mass weight) was given after overnight fasting to 20 non‐ HIV+ Co and 12 HIV+ HAART‐treated patients. Blood samples were taken before, 2h and 4h after MetLo in different 7‐d dietary situations, with NAC (1g/d) or with their usual diet (DO). The amino acids (Met, Hcy, Cys and Tau) and GSH were determined by HPLC and their inflow rate into circulation (plasma) estimated by the area under the curve (AUC). The difference between groups and diets were compared (p<0.05). When compared to DO the additional effects of MetLo to the NAC supplementation were markedly noted in HIV+ by increasing AUC of Hcy, Cys, Tau and GSH. Met matched the Co and Cys was found lower in both situations while GSH surpassed the Co values. When associated with NAC supplementation the MetLo increased Met probably by the Met spared effect of Cys and then increased Hcy probably by reducing remethylation activity. At the same time, trans‐sulfuration decreased probably feedbacking exogenous Cys. Thus, the failure of restoring normal Cys by MetLo in addition to NAC, in HIV+ patients seems related to increased flux of Cys into GSH and Tau pathways to strengthen the cell antioxidant capacity against the HIV progression. (FAPESP, CAPES and CNPq)