Browsing by Subject "Glutamine"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Effects of Maternal L-glutamine Supplementation on Fetus to Mitigate Teratogenic Effects of Alcohol(2013-12-05) Sawant, Onkar BalkrishnaWomen who drink alcohol during pregnancy are at high risk of giving birth to children with physical, behavioral or cognitive developmental problems called Fetal Alcohol Spectrum Disorders (FASD). Prenatal alcohol exposure is known to be associated with fetal growth restriction, disturbances in amino acid bioavailability, and alterations in fetal hemodynamics, blood flow and oxidative stress. Alterations in these parameters can persist into adolescence and low birth weight can lead to altered fetal development and programming, which can have lifelong consequences. Glutamine has been associated with fetal nitrogen and carbon metabolism, synthesis of the cellular anti-oxidant glutathione, apoptosis suppression, serving as a precursor for the synthesis of other amino acids, and increases in protein synthesis. Glutamine has been used clinically as a nutrient supplement in low birth weight infants. Therefore, it is hypothesized that repeated third trimester-equivalent maternal alcohol exposure in the sheep model decreases the bioavailability of amino acids, hampers fetal body growth, alters maternal-fetal hemodynamics, hampers uterine blood flow, alters fetal blood flow, increases cerebellar oxidative stress and that maternal L-glutamine supplementation may attenuate these negative developmental effects of prenatal alcohol exposure. Maternal alcohol exposure during the third trimester-equivalent period in the sheep model significantly reduced fetal body weight, height, crown-rump length and thoracic girth, and maternal glutamine supplementation successfully improved these fetal growth parameters in the alcohol+glutamine group. Maternal alcohol exposure during the third trimester-equivalent period resulted in significant reduction in glutamine and glutamine related amino acids bioavailability in maternal and fetal plasma as well as in the fetal amniotic and allantoic fluid. Maternal glutamine supplementation improved the bioavailability and efficacy of amino acids in the maternal and fetal compartment. This study also revealed that maternal alcohol exposure resulted in maternal acidemia, maternal hypercapnea, maternal hypoxemia as well as fetal acidemia and fetal hypercapnea, but not fetal hypoxemia. Maternal alcohol exposure during this period led to an increase in fetal mean arterial pressure, alterations in fetal brain blood flow and fetal cerebellar oxidative stress. Maternal alcohol exposure during the third trimester-equivalent period resulted in a more than 40% reduction in uterine artery blood flow. Maternal glutamine supplementation during the third trimester-equivalent period successfully attenuated the incidences of alcohol-induced maternal hypercapnea, fetal acidemia, alterations in fetal brain blood flow and improved the fetal cerebellar endogenous antioxidant status. Collectively these results signify that maternal glutamine supplementation mitigates negative developmental effects of prenatal alcohol exposure.Item Evaluation of Arginine and Glutamine as Dietary Supplements to Enhance Edwardsiella ictaluri Vaccine Effectivness in Channel Catfish(2012-02-14) Pohlenz Castillo, CamiloRapid expansion of the aquaculture industry in recent decades has resulted in infectious diseases emerging as a major constraint to fish production, causing large economical losses worldwide. Therefore, prevention practices are indispensable for maintaining the industry's profitability and sustainability. Vaccination is a proven effective strategy for disease control in aquaculture; however, improvements in vaccine efficacy are still needed. Because amino acid supplementation not only enhances fish growth but also immune responses, a series of experiments were conducted to test the hypothesis that dietary supplementation of arginine and glutamine, two amino acids with immunomodulatory roles, may promote growth and increase the efficacy of vaccination against Edwardsiella ictaluri in channel catfish. An initial experiment demonstrated that dietary arginine supplementation at 2 and 4% of diet enhanced growth and feed efficiency of channel catfish. Dietary arginine deficiency diminished plasma levels of arginine, citrulline, ornithine, glutamine and glutamate, and impaired innate performance of macrophages and neutrophils. In a separate experiment, dietary glutamine supplementation failed to enhance growth responses; however, supplementation at 2% of diet had strong positive effects on intestinal histology and enterocyte migration rate. In addition, serine, asparagine, glycine and threonine were increased in plasma of fish fed the diet with glutamine at 2%. A third experiment revealed that activated macrophages utilized large quantities of glutamine in media and to a lesser extent arginine. These two amino acids also were the most utilized by proliferating lymphocytes. Supplementing media with these amino acids positively modulated phagocytosis and bactericidal capacity of macrophages, as well as increased the proliferation rate of lymphocytes. A final experiment indicated that dietary supplementation of arginine (4%) and glutamine (2%) optimized the nutritional and immunological status of channel catfish, and enhanced responses to E. ictaluri vaccination. At the same time, this supplementation ameliorated some short-term adverse effects of vaccination on growth. Higher specific antibody titers, better lymphocyte responsiveness and survival to the bacterium were seen in vaccinated fish fed arginine- and glutamine-supplemented diets. These results support an expanded role of dietary arginine and glutamine manipulation as a tool to improve growth and vaccine efficacy of channel catfish.