Marcadores biológicos de adaptação ao treinamento esportivo: salivares e sanguíneos

Abstract

CHAPTER II: We investigated the levels of expression of 12 circulating miRNAs (c-miRNAs) involved in cell proliferation, differentiation, angiogenesis, inflammation and glycemic control following resistance exercise (RE) and dietary supplementation. Twelve subjects performed 10 sets of 10 repetitions with 80% of their respective one-repetition maximum (1RM) followed by either carbohydrate or carbohydrate/protein supplementation in a randomized single-blind counter-balanced design. Samples of blood were collected before RE, 03 and 24 hours afterwards. The relative expression data of all of the genes were analyzed using a two-way analysis of variance with repeated measures. The molecular response in the group that supplemented with protein was more pronounced for c-miRNAs involved in myogenesis, particularly hsa-miR-133a and -503. Both treatments revealed a differential expression of the c-miRNAs hsa-miR-126 and -16, which regulate angiogenesis. We argue that hsa-miR-133a is associated with satellite cell proliferation, and might be partially responsible for muscle hypertrophy following RE. Further, both the up- and down-regulation of hsa-miR-126 and -16, respectively, are likely to reflect neovascularization. CHAPTER III: During the last decade considerable interest has been directed towards using saliva as a surrogate matrix for blood in sports medicine. Saliva offers clear advantages over blood in regards to collection, handling and storage. Event though many analytical methods have been applied to study the response of a broad range of salivary analytes to sports and exercise, in our opinion little useful information has been accumulated thus far. There seems to be a disagreement in our approach to look for biomarkers and the information that is relevant for coaches. Thus, it is critical that we be able to discriminate between the effects that exercise evokes in salivary parameters and the information that a marker used to evaluate the physiological response to training should offer. Any molecule should not be considered a biological marker solely because of a statistical difference in their concentration in response to exercise. Phrased differently, biological markers in sports medicine must be associated with the variation of training load, identify a state of recovery or maladaptation or bear the potential to predict athletic success. On the other hand, some studies have in fact revealed great potential of salivary markers to monitor sports training. Here, we discuss the studies that identified salivary molecules that when used together with classical parameters of performance in exercise physiology might offer a deeper understanding on how athletes cope with training and hence, assist in the planning and prescription of training. In order to produce data that can be translated into the field, both scientists and coaches should participate in the aim and design of the studies as well as the interpretation and application of the findings. This review is an attempt to 1) emphasize how salivary biological markers should be employed and interpreted and 2) demonstrate the translational potential of salivary markers in sports medicine. CHAPTER IV: The collection of samples of saliva is noninvasive and straightforward, which turns saliva into an ideal fluid for monitoring the adaptive response to training. Here, we investigated the response of the salivary proteins alpha-amylase (sAA), chromogranin A (sCgA), and the concentration of total protein (sTP) as well as salivary nitrite (sNO2) in relation to plasma catecholamines and plasma nitrite (pNO2), respectively. The variation in these markers was compared to the intensity and load of training during a 21-week training season in 12 elite swimmers. Overall, the salivary proteins tracked the concentration of plasma adrenaline and were inversely correlated with the training outcomes. No correlations were observed between sNO2 and pNO2. However, sNO2 correlated positively with the intensity and load of training. We argue that the decrease in sympathetic activity is responsible for the decrease in the concentration of proteins throughout the training season. Furthermore, the increase in nitrite is likely to reflect changes in hemodynamics and regulation of vascular tone. The association of the salivary markers with the training outcomes underlines their potential as noninvasive markers of training status in professional athletes.