Search results for "hydrogenase"

NAD- and NADP-linked dehydrogenases in the sciatic nerve of rats injected with di-isopropylfluorophosphate.

1966

Expression of R-3-hydroxybutyrate dehydrogenase, a ketone body converting enzyme in heart and liver mitochondria of ruminant and non-ruminant mammals

1992

1. The properties of rat liver and bovine heart R-3-hydroxybutyrate dehydrogenase (BDH) have been extensively studied in the past 20 years, but little is known concerning the biogenesis and the regulation of this dehydrogenase over different species. 2. In addition, controversial results were often reported concerning the activity, the level and the subcellular location of this enzyme in ruminants. 3. BDH activity found in liver and kidney mitochondria from ruminants (cow and sheep) is low, while it is much higher in rat. 4. However, the enzyme activity is detected in microsomes and in cytosol of liver and of kidney cells from ruminants. These activities are not correlated to ketonaemia lev…

Effects of high-fat diet and physical activity on pyruvate dehydrogenase kinase-4 in mouse skeletal muscle

2012

Abstract Background The expression of PDK4 is elevated by diabetes, fasting and other conditions associated with the switch from the utilization of glucose to fatty acids as an energy source. It is previously shown that peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a master regulator of energy metabolism, coactivates in cell lines pyruvate dehydrogenase kinase-4 (PDK4) gene expression via the estrogen-related receptor α (ERRα). We investigated the effects of long-term high-fat diet and physical activity on the expression of PDK4, PGC-1α and ERRα and the amount and function of mitochondria in skeletal muscle. Methods Insulin resistance was induced by a high-fat (HF) d…

Relationship between Skin Temperature Variation and Muscle Damage Markers after a Marathon Performed in a Hot Environmental Condition

2021

This study aimed to assess the effect of a marathon running at a hot environmental temperature on the baseline skin temperature (Tsk) of the posterior day and to analyze the relationship between Tsk response and muscle damage markers variation. The Tsk, creatine kinase, and lactate dehydrogenase of 16 marathon runners were assessed four times before (15 days and 45 min) and after (24 h and 6 days) a marathon in a hot environment (thermal stress index = 28.3 ± 3.3 °C and humidity ~81%). The Tsk of thirteen different body regions of both right and left lower limbs were analyzed. Higher values after the marathon were observed than 45 min before in creatine kinase (174.3 ± 136.4 UI/L &lt

Biopterin metabolism and eNOS expression during hypoxic pulmonary hypertension in mice.

2013

International audience; Tetrahydrobiopterin (BH$_4$), which fosters the formation of and stabilizes endothelial NO synthase (eNOS) as an active dimer, tightly regulates eNOS coupling / uncoupling. Moreover, studies conducted in genetically-modified models demonstrate that BH$_4$ pulmonary deficiency is a key determinant in the pathogenesis of pulmonary hypertension. The present study thus investigates biopterin metabolism and eNOS expression, as well as the effect of sepiapterin (a precursor of BH$_4$) and eNOS gene deletion, in a mice model of hypoxic pulmonary hypertension. In lungs, chronic hypoxia increased BH$_4$ levels and eNOS expression, without modifying dihydrobiopterin (BH$_2$, t…

Sodium-hydrogen exchange inhibition: novel strategy to prevent myocardial injury following ischemia and reperfusion.

1999

Activation of Na+/H+ exchange and subsequent calcium overload in cardiac myocytes appear to play an important role in myocardial tissue injury following ischemia and reperfusion. Results of several in vitro studies in isolated myocytes and heart preparations and in vivo studies in pigs and rats have suggested that inhibition of Na+/H+ exchange is an effective means to prevent lethal reperfusion injury, arrhythmia, and improve myocardial contractile dysfunction. In patients with acute myocardial infarction (MI), any preventive agent is administered immediately before or shortly after reperfusion, rather than before the occurrence of coronary occlusion. The direct interventional approach to t…

Increased susceptibility to lipid peroxidation in skeletal muscles of dystrophic hamsters.

1989

The results showed that the total content of lipids, which could be peroxidized with Fe(2 +)/ascorbate stimulation in vitro, was 45.4% and 53.7% higher than normal in the dystrophic hamster muscle at the age of 1 and 3 months, respectively. Correspondingly, the susceptibility to lipid peroxidation (stimulated by ADP-chelated iron at 37 degrees C) was 38.6-74.3% higher in dystrophic muscles. The increases were not related to necrotic lesions and inflammation observed. The activities of glucose-6-phosphate dehydrogenase, glutathione reductase, thioredoxin reductase and catalase were increased in dystrophic muscles but those of superoxide dismutases and glutathione peroxidase were unaffected.

Differential effects of oxidized LDL on apolipoprotein AI and B synthesis in HepG2 cells

2006

Oxidized low-density lipoproteins (Ox-LDL) are key elements in atherogenesis. Apolipoprotein AI (apoAI) is an active component of the antiatherogenic high-density lipoproteins (HDL). In contrast, plasma apolipoprotein B (apoB), the main component of LDL, is highly correlated with coronary risk. Our results, obtained in HepG2 cells, show that Ox-LDL, unlike native LDL, leads to opposite effects on apoB and apoAI, namely a decrease in apoAI and an increase in apoB secretion as evaluated by [(3)H]leucine incorporation and specific immunoprecipitation. Parallel pulse-chase studies show that Ox-LDL impaired apoB degradation, whereas apoAI degradation was increased and mRNA levels were decreased.…

Oxygen and substrate deprivation on isolated rat cardiac myocytes : temporal relationship between electromechanical and biochemical consequences

1990

The effects of hypoxia and reoxygenation on action potentials (AP), contractions, and certain biochemical parameters were studied in isolated rat ventricular myocytes in monolayer culture in the presence and absence of glucose. Substrate deprivation alone had no influence on the basal properties. In the presence of glucose, a 4-h hypoxic treatment caused only a moderate decrease in AP amplitude and rate. In substrate-free conditions, hypoxia induced a gradual decline in plateau potential level and in AP duration and rate, followed by rhythm abnormalities and a failure of the electromechanical coupling. Spontaneous AP generation then ceased, and the resting potential decreased with increase…

Pharmacokinetic evaluation of mycophenolate mofetil for pemphigus.

2011

Introduction: Pemphigus is an autoimmune blistering disease of the skin and mucous membranes characterized by the development of autoantibodies against the desmosomal proteins, desmoglein-1 and -3. Before the advent of corticosteroids, therapy was almost fatal. The introduction of high-dose corticosteroid therapy has reduced mortality rates to similar to 10%, but long-term use of steroids can lead to side effects, many of which are severe and associated with significant morbidity. Thus, the major goal of pemphigus therapy has been to reduce the patient's cumulative exposure to systemic corticosteroids. Over the last 2 decades, a range of corticosteroid-sparing immunosuppressive agents have …