Physiology & Biochemistry 377 de Oliveira VN et al. Changes in the Salivary Biomarkers … Int J Sports Med 2010; 31: 377–381 accepted after revision January 25, 2010 Bibliography DOI http://dx.doi.org/ 10.1055/s-0030-1248332 Published online: March 18, 2010 Int J Sports Med 2010; 31: 377–381 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0172-4622 Correspondence Dr. Foued Salmen Espindola Universidade Federal de Uberladia Instituto de Genética e Bioquimica Av. Para 1720 38400982 Uberlândia Brazil Tel.: + 34/32182477 Fax: + 34/32182203 fouedespindola@gmail.com Key words ● ▶ exercise ● ▶ lactate ● ▶ salivary alpha-amylase ● ▶ protein ● ▶ anaerobic threshold ● ▶ electrophoresis Changes in the Salivary Biomarkers Induced by an Effort Test [21, 30]. Previous studies have shown that a sali- vary threshold exists beyond which a continuous increase in these analytes may serve as a salivary biomarker of exercise intensity [4, 6, 9]. Activity of the sympathetic nervous system increases progressively with intensity of exercise [32], altering some salivary components [3, 10, 38]. Bortolini et al. [4] investigated whether the total protein concentration of whole saliva (TPWS) reflects the anaerobic threshold during an incremental exercise test, and they observed a profound correlation between the total salivary protein threshold (PAT) and the BLT. Analysis of salivary proteins in rat parotid saliva revealed that the protein content in the parotid is mark- edly influenced by the type of stimulation (sym- pathetic or parasympathetic) used to induce secretion [1]. It has been proposed that salivary alpha-amylase (sAA) activity is regulated by the sympathetic- adrenal medullary (SAM) system through the action of norepinephrine on the salivary glands [8, 34, 40]. Activity of sAA increases in response Introduction ▼ Traditional biochemical approaches for studying individual proteins have provided structures and functions of a number of major salivary proteins. However, many salivary proteins and their func- tions remain uncharacterized [17]. Physical exer- cise induces biochemical changes in the body, which modify blood and saliva analytes among other body fluids [2, 10, 18]. Based on these observations, analyzing changes in the salivary protein profile may help to identify novel biomar- kers for work load, recovery and injury. Measuring salivary analytes , such as total pro- tein, alpha-amylase, electrolytes, lactate, cortisol and catecholamines may represent a noninvasive method to determine the relationship between intensity of exercise and the blood lactate thresh- old (BLT) [4, 6, 9]. The BLT is characterized by the transition from a linear to an exponential increase in blood lactate concentration, and its measure- ment has been of great use in both experimental and routine studies of physical performance Authors V. N. de Oliveira 1 , A. Bessa 1 , R. P. M. S. Lamounier 1 , M. G. de Santana 2 , M. T. de Mello 2 , F. S. Espindola 1 Affiliations 1 Universidade Federal de Uberlândia, Instituto de Genética e Bioquímica, Uberlândia, Brazil 2 Universidade Federal de São Paulo, Departamento de Psicobiologia, São Paulo, Brazil Abstract ▼ Physical exercise induces biochemical changes in the body that modify analytes in blood and saliva among other body fluids. This study analyzed the effect of an incremental effort test on the salivary protein profile to determine whether any specific protein is altered in response to such stress. We also measured thresholds of salivary alpha amy- lase, total salivary protein and blood lactate and searched for correlations among them. Twelve male cyclists underwent a progressive test in which blood and saliva samples were collected simultaneously at each stage. The salivary total protein profile revealed that physical exercise primarily affects the polypeptide corresponding to salivary alpha-amylase, the concentration of which increased markedly during the test. We observed thresholds of salivary alpha-amylase (sAAT), total salivary protein (PAT) and blood lactate (BLT) in 58 %, 83 % and 100 % of our sam- ple, respectively. Pearson’s correlation indicates a strong and significant association between sAAT and BLT (r = 0.84, p < 0.05), sAAT and PAT (r = 0.83, p < 0.05) and BLT and PAT (r = 0.90, p < 0.05). The increased expression of the sali- vary alpha-amylase (sAA) polypeptide suggests that sAA is the main protein responsible for the increase in total protein concentration of whole saliva. Therefore, monitoring total protein con- centration is an efficient tool and an alternative noninvasive biochemical method for determin- ing exercise intensity. Downloaded by: Dot. Lib Information. Copyrighted material.