Acute Phase Immune Response to Exercise Coexists with Decreased Neutrophil Antioxidant Enzyme Defences

Long-duration or damaging exercise initiates reactions that resemble the acute phase response to infection and induces neutrophil priming for oxidative activity. Our objective was to establish the status of the antioxidant defences and of the oxidative equilibrium in the neutrophils of sportsmen prior to and after intense physical exercise. Nine voluntary male professional cyclists participated in this study. The exercise was a cycling mountain stage (171 km) and the cyclists took a mean &#45 SEM of 270 &#45 12 min to complete it. We determined the activities of catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), the levels and activity of superoxide dismutase (SOD), the concentrations of ascorbate, glutathione and glutathione disulphide (GSSG) and DNA levels in neutrophils. The cycling stage decreased enzyme activities expressed per DNA units: CAT (33%), SOD (38%), GPx (65%); increased ascorbate concentration in neutrophils and decreased the GSH/GSSG ratio and the enzyme activities expressed per DNA units. Neutrophils could contribute to plasma antioxidant defences against oxidative stress induced by exercise because they probably provide antioxidant enzymes and ascorbate.     

Hypophagia and induction of serotonin transporter gene expression in raphe nuclei of male and female rats after short-term fluoxetine treatment

Serotonin (5-HT) is one of the regulators of feeding in humans. Drugs acting on the serotoninergic system are used to treat bulimia nervosa and to enhance the effect of hypocaloric diets in overweight subjects. They act rapidly to normalise feeding when used to treat eating-related problems. To explore the role of the 5-HT transporter (serotonin transporter (SERT)) in the short-term action of serotonin selective reuptake inhibitor fluoxetine, rats were i.p. given the drug for five consecutive days. Acute administration of fluoxetine in male and female rats produced a strong reduction in food intake, an effect that held up when daily treatment was maintained for five consecutive days. This reduction translated into a diminution of body weight that was statistically significant in the case of the males. As a reflection of the body weight change in rats killed after the fifth daily drug injection, retroperitoneal fat pad also decreased; a diminution that was statistically significant in the case of male rats. In these conditions, plasma leptin levels of both male and female rats were lower than in untreated animals. While acute fluoxetine administration did not modify SERT gene expression, subchronic drug treatment increased the content of SERT mRNA in the midbrain raphe complex of both rat genders. These findings may contribute to explain the role of SERT in fluoxetine action on binging and as an adjunct to hypocaloric diets.     

Coenzyme Q10 deficiency in mitochondrial DNA depletion syndromes

We evaluated coenzyme Q₁₀ (CoQ) levels in patients studied under suspicion of mitochondrial DNA depletion syndromes (MDS) (n = 39). CoQ levels were quantified by HPLC, and the percentage of mtDNA depletion by quantitative real-time PCR. A high percentage of MDS patients presented with CoQ deficiency as compared to other mitochondrial patients (Mann–Whitney-U test: p = 0.001). Our findings suggest that MDS are frequently associated with CoQ deficiency, as a possible secondary consequence of disease pathophysiology. Assessment of muscle CoQ status seems advisable in MDS patients since the possibility of CoQ supplementation may then be considered as a candidate therapy.     

Hydrogen peroxide generated by over-expression of cytosolic superoxide dismutase in transgenic plums enhances bacterial canker resistance and modulates plant defence responses

Molecular Biology Reports - H2O2 generated during the oxidative burst, plays important roles in plant defenses responses against pathogens. In this study we examined the role of H2O2 on bacterial...