Objective: To determine the effects of single nucleotide polymorphisms (SNPs) in the adrenergic β2-receptor gene (ADRB2, rs1042713, and rs1042714) and epithelial Na channel gene (SCNN1A, rs2228576) on cycling performance after the inhalation of salbutamol.
Design: Randomized double-blind, mixed-model repeated measures.
Setting: University Research Setting.
Epigenetics refers to long-term modifications of gene activity that can be inherited, either somatically or transgenerationally, but that are independent of alterations in the primary base sequence of the organism's DNA. These changes can include chemical modifications of both the DNA bases and the proteins that associate with the DNA helices to form chromatin, the nucleic acid:protein complex of which the chromosomes are comprised. Epigenetic modifications can affect the accessibility of the DNA for transcription factors (the DNA-binding proteins that specify which genes are to be active or silent by modulating the recruitment of the transcriptional machinery that reads the information encoded in the sequence) and thereby regulate the expression of genes and alter the phenotype of the organism.
View Article and Find Full Text PDFRationale: Salbutamol may affect lung function and exercise performance differently in individuals with and without asthma.
Objectives: To compare the effects of inhaled salbutamol on lung function, exercise performance and respiratory parameters during cycling exercise in athletes with a positive response to a eucapnic voluntary hyperpnoea (EVH+) and negative (EVH-) challenge, indicative of exercise-induced bronchoconstriction.
Methods: In a randomised controlled trial with a crossover design, a total of 49 well-trained male athletes (14 EVH+ and 35 EVH-) performed two simulated 10 km time-trials on a cycle ergometer 60 min after the inhalation of either 400 μg of salbutamol or a placebo.
Respir Physiol Neurobiol
October 2013
Haematological responses throughout 4 w of initial acclimation (IA) and three paradigms of re-acclimation (RA) to hypoxia (FI(O₂)) were examined in female mice. We hypothesised that (i) haematological responses would be increased during re-exposure, resulting in greater O₂-carrying capacity in RA compared to IA; and (ii) further improvements would occur when abbreviating the de-acclimation period to 1 w (RA↓DA) or extending the IA period to 8 w (RA↑IA). The serum [EPO] response was blunted in all RA groups compared to IA but the resulting reticulocyte response was similar in all experimental groups.
View Article and Find Full Text PDFHomologous (or allogeneic) blood doping, in which blood is transferred from a donor into a recipient athlete, is the easiest, cheapest, and fastest way to increase red cell mass (hematocrit) and therefore the oxygen-carrying capacity of the blood. Although thought to have been rendered obsolete as a doping strategy by the increased use of rhEPO to increased hematocrits, there is evidence that athletes are still using this potentially dangerous method to improve endurance performance. Current testing for homologous blood doping is based on identification of mixed populations of red blood cells by flow cytometry.
View Article and Find Full Text PDFCan Bull Med Hist
January 2012
From 1968 to 1998, female Olympic athletes were expected to prove their "femininity," ostensibly to stop male "ringers" from passing themselves off as female competitors. Rumours that men were competing in drag had been around since at least the 1936 games. The sex tests started out as simple anatomical examinations--the "nude parade," but rapidly progressed to cellular-based tests (the presence of a Barr body), and eventually to molecular-based tests (the absence of the SRY gene).
View Article and Find Full Text PDFThe overall purpose of this study was to examine the effect of deterministic media reports, linking genetics to inactivity, in relation to inactive people's social cognitions concerning physical activity involvement. Sixty three inactive university students were randomly allocated to one of three experimental conditions (control, genetically-primed, experientially-primed) and completed measures of instrumental and affective attitudes, subjective norms, self-efficacy, and exercise intentions. One week later participants in the two experimental conditions were provided with a bogus newspaper report that either reflected a genetic explanation for physical inactivity or an experiential basis for inactivity.
View Article and Find Full Text PDFIntermittent hypoxia (IH) has been shown to alter the ventilatory and cardiovascular responses to submaximal exercise; however, the effect of IH on the cerebral blood flow (CBF) response to submaximal exercise has not been determined. This study tested the hypothesis that IH would blunt the CBF response during eucapnic and hypercapnic exercise. Nine healthy males underwent 10 consecutive days of isocapnic IH (oxyhaemoglobin saturation = 80%, 1 h day(-1)).
View Article and Find Full Text PDFWe analyzed 8.55 million LongSAGE tags generated from 72 libraries. Each LongSAGE library was prepared from a different mouse tissue.
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