Publications (24) View all
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Article: Effects of DHA-Rich Fish Oil Supplementation on Lymphocyte Function Before and After a Marathon Race.
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ABSTRACT: Purpose: To investigate the effects of docosahexaenoic-(DHA)-rich fish oil (FO) supplementation on lymphocyte function before and after a marathon race. Methods: Twenty-one athletes participated in this study. Eight marathon runners were supplemented with 3 g of FO daily for 60 d (FO group), and 13 athletes were not supplemented (C group). The following measures of lymphocytes were taken before and after the marathon: cell proliferation, cytokine production (IL-2, IL-10, TNF-, and IL-4), and signs of cell death. Results: In the C group, the marathon had no effect on lymphocyte proliferation, DNA fragmentation, or mitochondrial membrane polarization; however, the marathon increased phosphatidylserine externalization (by 2.5-fold), induced a loss of plasma membrane integrity (by 20%), and decreased IL-2, TNF-, and IL-10 production (by 55%, 95%, and 50%, respectively). FO supplementation did not prevent lymphocyte death induced by the marathon, as indicated by cell viability, DNA fragmentation, and phosphatidylserine externalization. However, FO supplementation increased lymphocyte proliferation before and after the marathon, and before the race, FO supplementation decreased IL-2, TNF-, and IL-10 production in concanavalin-A-stimulated lymphocytes (by 55%, 95%, and 58%, respectively) compared with cells from the C group. The production of cytokines was not altered before or after the race in the FO group. Conclusions: DHA-rich FO supplementation increased lymphocyte proliferation and prevented a decrease in cytokine production, but it did not prevent lymphocyte death induced by participation in the marathon. Overall, DHA rich-FO supplementation has beneficial effects in preventing some of the changes in lymphocyte function induced by marathon participation.International Journal of Sport Nutrition and Exercise Metabolism 04/2013; 23(2):161-9. -
Article: Changes in lymphocyte and neutrophil function induced by a marathon race.
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ABSTRACT: The aim of this study was to investigate the changes in lymphocyte and neutrophil selected functions before and after a marathon race. Fifteen professional athletes were recruited, and the following parameters were measured: plasma concentrations of IL-1ra, IL-6, IL-8, IL-10, TNF-α and C-reactive protein (CRP); neutrophil phagocytic capacity; cytokine production by neutrophils and lymphocytes and signs of neutrophil and lymphocyte death. The marathon race had no effect on CRP levels, but plasma concentrations of IL-6 and IL-1ra were increased. Although no effect was observed on the production of IL-6, IL1-ra, TNF-α, IL-1β and IL-8 by unstimulated or stimulated neutrophils, a decrease in neutrophil phagocytic activity was observed immediately following the marathon. A high percentage of neutrophils undergoing apoptosis was observed due to the intense training regimen, whereas the percentages of apoptotic neutrophils were reduced after the race. The production of IL-2, TNF-α, IL-1β and IL-10 by lymphocytes was decreased by 50%-80%, and the percentage of apoptotic and necrotic lymphocytes was increased by 42% and fourfold, respectively, as a result of the race. In conclusion, the increase in plasma levels of IL-6, IL-8, IL-1ra and IL-10 after the race was not due to the production of the cytokines by neutrophils or lymphocytes. In fact, the marathon led to a decrease in lymphocyte and neutrophil function, and the diminished function was more pronounced in lymphocytes, indicating an impairment in acquired immunity. Copyright © 2012 John Wiley & Sons, Ltd.Cell Biochemistry and Function 09/2012; · 1.77 Impact Factor -
Article: Persistence of inflammatory response to intense exercise in diabetic rats.
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ABSTRACT: In this study we evaluated the onset and resolution of inflammation in control and streptozotocin-induced diabetic rats subjected to a single session of intense exercise. The following measurements were carried out prior to, immediately after, and 2 and 24 hours after exercise: plasma levels of proinflammatory cytokines (TNF-α, IL-1β, IL-6, CINC-2α/β, MIP-3α, and IL-6), immunoglobulins (IgA and IgM), acute phase proteins (CRP and C3), and creatine kinase (CK) activity. We also examined the occurrence of macrophage death by measurements of macrophages necrosis (loss of membrane integrity) and DNA fragmentation. An increase was observed in the concentration of IL-1β (3.3-fold) and TNF-α (2.0-fold) and in the proportion of necrotic macrophages (4.5-fold) in diabetic rats 24 hours after exercise, while the control group showed basal measurements. Twenty-four hours after the exercise, serum CK activity was elevated in diabetic rats but not in control animals. We concluded that lesion and inflammations resulting from intense exercise were greater and lasted longer in diabetic animals than in nondiabetic control rats.Experimental Diabetes Research 01/2012; 2012:213986. · 1.20 Impact Factor -
Article: Effects of moderate electrical stimulation on reactive species production by primary rat skeletal muscle cells: cross talk between superoxide and nitric oxide production.
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ABSTRACT: The effects of a moderate electrical stimulation on superoxide and nitric oxide production by primary cultured skeletal muscle cells were evaluated. The involvement of the main sites of these reactive species production and the relationship between superoxide and nitric oxide production were also examined. Production of superoxide was evaluated by cytochrome c reduction and dihydroethidium oxidation assays. Electrical stimulation increased superoxide production after 1 h incubation. A xanthine oxidase inhibitor caused a partial decrease of superoxide generation and a significant amount of mitochondria-derived superoxide was also observed. Nitric oxide production was assessed by nitrite measurement and by using 4,5-diaminofluorescein diacetate (DAF-2-DA) assay. Using both methods an increased production of nitric oxide was obtained after electrical stimulation, which was also able to induce an increase of iNOS content and NF-κB activation. The participation of superoxide in nitric oxide production was investigated by incubating cells with DAF-2-DA in the presence or absence of electrical stimulation, a superoxide generator system (xanthine-xanthine oxidase), a mixture of NOS inhibitors and SOD-PEG. Our data show that the induction of muscle contraction by a moderate electrical stimulation protocol led to an increased nitric oxide production that can be controlled by superoxide generation. The cross talk between these reactive species likely plays a role in exercise-induced maintenance and adaptation by regulating muscular glucose metabolism, force of contraction, fatigue, and antioxidant systems activities.Journal of Cellular Physiology 08/2011; 227(6):2511-8. · 3.87 Impact Factor -
Article: Amino acids and diabetes: implications for endocrine, metabolic and immune function.
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ABSTRACT: Aberrant alterations in glucose and lipid concentrations and their pathways of metabolism are a hallmark of diabetes. However, much less is known about alterations in concentrations of amino acids and their pathways of metabolism in diabetes. In this review we have attempted to highlight, integrate and discuss common alterations in amino acid metabolism in a wide variety of cells and tissues and relate these changes to alterations in endocrine, physiologic and immune function in diabetes.Frontiers in Bioscience 01/2011; 16:315-39. · 3.52 Impact Factor
