Search results for "oxidation"
showing 10 items of 1913 documents
Acute Metabolic Response, Energy Expenditure, and EMG Activity in Sitting and Standing
2017
Purpose While merely standing up interrupts sedentary behavior, it is important to study acute metabolic responses during single bouts of sitting and standing to understand the physiological processes affecting the health of office workers. Methods Eighteen healthy middle-age women 49.4 ± 7.9 yr old (range: 40–64) with a body mass index of 23.4 ± 2.8 kg·m−2 volunteered for this laboratory-based randomized crossover trial where they performed 2 h desk work in either sitting or standing postures after overnight fasting. Muscle activity (normalized to walking at 5 km·h−1), respiratory gas exchange, and blood samples were assessed after glucose loading (75 g). Results Compared with seated work,…
Antioxidant treatment for impaired hypoxic ventilatory responses in experimental diabetes in the rat
2018
Inflammation, tissue hypoxia, and impaired hypoxic ventilatory response (HVR) are the intricately entwined features of diabetes which perpetuate the disease and its sequelae. Hyperglycemia, notably, is an oxygen consuming process due to enhanced cellular metabolism. Oxidative stress underlies diabetic pathogenesis and also is a crucial modulator of the hypoxic chemoreflex. The present study seeks to determine if suppressed ventilation in diabetes could be improved by antioxidant treatment. The study was performed in streptozotocin-induced diabetes in awake rats. Two weeks into full-fledged diabetes, the rats were divided into mangiferin (potent natural antioxidant)-treated and untreated, wi…
ERK1 and ERK2 activation modulates diet-induced obesity in mice
2017
IF 3.112; International audience; Obesity is a worldwide problem, and dietary lipids play an important role in its pathogenesis. Recently, Erk1 knock-out (ERK1(-/-)) mice have been shown to exhibit low preference for dietary fatty acids. Hence, we maintained Erk1(-/-) mice on a high-fat diet (HFD) to assess the implication of this mitogen-activated protein (MAP) kinase in obesity. The Erk1(-/-) mice, fed the HFD, were more obese than wild-type (WT) animals, fed the same diet. Erk1(-/-) obese mice gained more fat and liver mass than WT obese animals. No difference was observed in daily food and energy intake in HFD-fed both group of animals. However, feed efficiency was higher in Erk1(-/-) t…
POSTPRANDIAL HYPERGLYCEMIA IS A DETERMINANT OF PLATELET ACTIVATION IN EARLY 2 DIABETES MELLITUS
2010
BACKGROUND: Chronic hyperglycemia is a major contributor to in vivo platelet activation in diabetes mellitus. OBJECTIVES: To evaluate the effects of acarbose, an alpha-glucosidase inhibitor, on platelet activation and its determinants in newly diagnosed type 2 diabetic patients. METHODS: Forty-eight subjects (26 males, aged 61 +/- 8 years) with early type 2 diabetes (baseline hemoglobin A(1c) < or = 7% and no previous hypoglycemic treatment) were randomly assigned to acarbose up to 100 mg three times a day or placebo, and evaluated every 4 weeks for 20 weeks. The main outcome measures were urinary 11-dehydro-thromboxane (TX)B(2) (marker of in vivo platelet activation) and 8-iso-prostaglandi…
Antioxidant effect of Ajuga iva aqueous extract in streptozotocin-induced diabetic rats.
2009
The purpose of this study was to investigate the possible antioxidant effect of an aqueous extract of Ajuga iva (Ai) in streptozotocin (STZ)-induced diabetic rats. Twelve diabetic rats were divided into two groups fed a casein diet supplemented or not with Ai (0.5%), for 4 weeks. In vitro, the Ai extract possessed a very high antioxidant effect (1 mg/ml was similar to those of trolox 300 mmol/l). The results indicated that plasma thiobarbituric acid reactive substances (TBARS) values were reduced by 41% in Ai-treated compared with untreated diabetic rats. TBARS concentrations were lower 1.5-fold in liver, 1.8-fold in heart, 1.9-fold in muscle and 2.1-fold in brain in Ai-treated than untreat…
Fructose-enriched diet modifies antioxidant status and lipid metabolism in spontaneously hypertensive rats
2005
Abstract Objective High-fructose consumption in industrial countries has been shown to induce metabolic abnormalities or syndrome X. Changes in antioxidant defense are unknown in hypertension associated with metabolic disorders induced by high-fructose feeding. Methods Twenty spontaneously hypertensive rats were assigned to one of two groups; one received a fructose-enriched diet (60% fructose) and the other a starch diet. After a 13-wk diet period, total antioxidant status was assessed in the blood and liver by monitoring the rate of free radical-induced red blood cell hemolysis. Antioxidants (enzymes and vitamins) were determined in blood and liver. Gene expression of antioxidant enzymes …
Protein oxidation in a group of subjects with metabolic syndrome.
2013
Abstract Aims To examine the protein oxidation, marker of the oxidative stress, in metabolic syndrome (MS). Methods We enrolled 106 subjects (45 women and 61 men) with MS of which 43 (14 women and 27 men) were with diabetes mellitus and 63 (31 women and 32 men) were without diabetes mellitus, and 54 subjects (19 women and 35 men) as control group. The protein oxidation, expressed as carbonyl groups, was measured by an enzyme-like immunosorbent assay (ELISA) kit (BioCell PC test kit, Enzo Life Sciences AG, Switzerland). Results In the whole group of MS subjects, in comparison with control group, a significant increase in carbonyl groups was present. The same datum was also evident between co…
Associations of resting and peak fat oxidation with sex hormone profile and blood glucose control in middle-aged women.
2022
Background and Aims Menopause may reduce fat oxidation. We investigated whether sex hormone profile explains resting fat oxidation (RFO) or peak fat oxidation (PFO) during incremental cycling in middle-aged women. Secondarily, we studied associations of RFO and PFO with glucose regulation. Method and Results We measured RFO and PFO of 42 women (age 52–58 years) with indirect calorimetry. Seven participants were pre- or perimenopausal, 26 were postmenopausal, and nine were postmenopausal hormone therapy users. Serum estradiol (E2), follicle-stimulating hormone, progesterone, and testosterone levels were quantified with immunoassays. Insulin sensitivity (Matsuda index) and glucose tolerance (…
Oxidant stress: the role of nutrients in cell-lipoprotein interactions
1999
Oxidant stress is increasingly becoming an important hypothesis to explain the genesis of several pathologies, including cancer, atherosclerosis and also ageing. Beside a few rare genetic defects, dietary factors are thought to play a key role in the regulation of the production of reactive oxygenated species. An imbalance between nutrients, and in particular those involved in antioxidant status, could explain the onset of an enhanced production of free radicals. We will briefly review information concerning oxidation of lipids and lipoproteins which lead to atherothrombosis. We also present new findings supporting a role for blood platelets in generating oxidant species. New data are also …
Oleanonic acid, a 3-oxotriterpene from Pistacia, inhibits leukotriene synthesis and has anti-inflammatory activity.
2001
One of the best known bioactive triterpenoids is oleanolic acid, a widespread 3-hydroxy-17-carboxy oleanane-type compound. In order to determine whether further oxidation of carbon 3 affects anti-inflammatory activity in mice, different tests were carried out on oleanolic acid and its 3-oxo-analogue oleanonic acid, which was obtained from Pistacia terebinthus galls. The last one showed activity on the ear oedema induced by 12-deoxyphorbol-13-phenylacetate (DPP), the dermatitis induced by multiple applications of 12-O-tetradecanoyl-13-acetate (TPA) and the paw oedemas induced by bradykinin and phospholipase A2. The production of leukotriene B4 from rat peritoneal leukocytes was reduced by ol…