Evolution of potential biomarkers of acute muscle injury after physical exercise

Skeletal muscle injury is a frequent event and diagnosis using the classical blood markers sometimes produces unsatisfactory results. Therefore, objective of the study was to detect new biomarkers in plasma, saliva and urine in response to acute muscle damage induced by physical exercise. A cross-sectional study was conducted with 27 American football players. Before the physical exercises (T0), 60 minutes (T1) and 24 hours (T2) after physical exercise, was determined the clinical, biochemical and molecular parameters, including ADA, TBARS, leukocytes, lymphocytes and comet assay. The serum ADA was significantly higher in T1 and T2, in the urine there was a significant increase in T1, in the saliva there was no significant differences. There was an increase in serum TBARS in T2, saliva and urine in T1. The leukocytes increased in T1 and decreased in T2. Through the comet assay was observed significant DNA damage in T1 and T2. Serum and urinary ADA activity, serum, urinary and salivary TBARS are robust and promising biomarkers of acute muscle injury and that the comet assay allows a quick and effective evaluation of DNA lesions induced by physical exercise and could be used to monitor athletes avoiding injuries that are more serious.

Effects of purine nucleotide administration on purine nucleotide metabolism in brains of heroin-dependent rats

ABSTRACT Heroin is known to enhance catabolism and inhibit anabolism of purine nucleotides, leading to purine nucleotide deficiencies in rat brains. Here, we determined the effect of exogenous purine nucleotide administration on purine nucleotide metabolism in the brains of heroin-dependent rats. Heroin was administrated in increasing doses for 9 consecutive days to induce addiction, and the biochemical changes associated with heroin and purine nucleotide administration were compared among the treated groups. HPLC was performed to detect the absolute concentrations of purine nucleotides in the rat brain cortices. The enzymatic activities of adenosine deaminase (ADA) and xanthine oxidase (XO) in the treated rat cortices were analyzed, and qRT-PCR was performed to determine the relative expression of ADA, XO, adenine phosphoribosyl transferase (APRT), hypoxanthine-guaninephosphoribosyl transferase (HGPRT), and adenosine kinase (AK). Heroin increased the enzymatic activity of ADA and XO, and up-regulated the transcription of ADA and XO. Alternatively, heroin decreased the transcription of AK, APRT, and HGPRT in the rat cortices. Furthermore, purine nucleotide administration alleviated the effect of heroin on purine nucleotide content, activity of essential purine nucleotide metabolic enzymes, and transcript levels of these genes. Our findings therefore represent a novel, putative approach to the treatment of heroin addiction.