The potential role of sulfur amino acids in the acute inflammatory response

dc.contributor.authorMedina, Gerardo
dc.contributor.examiningcommitteeBlewett, Heather (Food and Human Nutritional Science) O, Karmin (Animal Science) Wu, Guoyao (Animal Science, Texas A&M University)en_US
dc.contributor.supervisorHouse, James (Food and Human Nutritional Science)en_US
dc.date.accessioned2021-09-10T11:12:20Z
dc.date.available2021-09-10T11:12:20Z
dc.date.copyright2021-08-13
dc.date.issued2021-08en_US
dc.date.submitted2021-08-13T20:20:28Zen_US
dc.degree.disciplineFood and Human Nutritional Sciencesen_US
dc.degree.levelDoctor of Philosophy (Ph.D.)en_US
dc.description.abstractThe sulfur amino acids (SAA), methionine (Met) and cysteine (Cys) have an important role in the acute inflammatory response, including regulating the production of reactive oxygen species (ROS) and the development of cardiovascular disease (CVD). The objectives of the current study were 1) study alterations in Met cycle on the acute inflammatory response 2) investigate the in vivo temporal changes induced by an intraperitoneal (IP) injection of lipopolysaccharide (LPS), and 3) identify the potential effect of altered dietary SAA on the acute inflammatory response in male Wistar rats. The LPS dose that induced inflammation to a greater extent was 100 μg/kg compared with 50 μg/kg. LPS at 100 μg/kg presented a significant increase in both temperatures (p<0.05) and cytokine tumor necrosis factor-alpha (TNF-α) (p<0.001) post-injection compared with control. Additionally, at a dose of 100 μg/kg showed a significant increase in temperature when compared with 50 μg/kg at 120min (p<0.05) and 240 min (p<0.05). Plasma biochemical analyses revealed that the TNF-α area under the curve in dietary SAA of 50Met:50Cys was significantly higher (p<0.004) when compared with a dietary SAA ratio of 100Met:0Cys; however, no significant differences were observed in the percentage of leukocytes that were neutrophils. Additionally, a diet with a balanced Met:Cys ratio increased concentrations of plasma Cys and glutathione (GSH) after 4h. Adequate dietary intake of SAA play an important role in the immune response synthetizing intracellular antioxidant including GSH. An increase in the requirement of SAA or impairment in the SAA metabolism under infection can affect negatively the production of pro-inflammatory cytokines such as TNF-α, IL-6 and neutrophil proliferation. Perturbations in the transmethylation (TM) and transsulfuration (TS) pathways can lead to hyperhomocysteinemia (HHcy; plasma homocysteine >15 µmol/L) increasing the risk of coronary artery disease or kidney failure. Overall, the results presented in this study serve to highlight the potential effect of altered dietary SAA ratio in a model of systemic inflammatory response syndrome in addition to demonstrating the potential negative effect of impairment in the SAA metabolism.en_US
dc.description.noteOctober 2021en_US
dc.identifier.citationVancuveren_US
dc.identifier.urihttp://hdl.handle.net/1993/35947
dc.language.isoengen_US
dc.rightsopen accessen_US
dc.subjectSulfur amino acidsen_US
dc.subjectAcute inflammationen_US
dc.subjectWistar ratsen_US
dc.subjectGlutathioneen_US
dc.subjectLPSen_US
dc.titleThe potential role of sulfur amino acids in the acute inflammatory responseen_US
dc.typedoctoral thesisen_US
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