The effect of physical exercise on salivary secretion of MUC5B, amylase and lysozyme

Abstract

ObjectivesSaliva secretion is regulated by the autonomic nervous system. Parasympathic stimuli increase the secretion of water and mucin MUC5B, whereas sympathetic stimuli such as physical exercise increase the secretion of amylase and other proteins. In the present study we investigated the effect of physical exercise, as a sympathetic stimulus, on salivary flow rate and output of MUC5B, amylase, lysozyme and total protein. DesignUnstimulated whole saliva was collected before exercise (1), after 10min exercise with moderate intensity by running with a heart rate around 130 beats per minute (2), followed by 10min exercise with high intensity by running to exhaustion (3) and after 30min recovery (4). Salivary flow rate, protein and MUC5B concentration, and amylase and lysozyme activity were determined. Saliva protein composition was analysed using SDS-PAGE and immunoblotting. ResultsSalivary flow rate, protein and lysozyme secretion increased after exercise with moderate intensity and increased further after exercise with high intensity (p<0.01). Amylase and MUC5B increased after exercise with moderate intensity (p<0.0001), but did not differ significantly between moderate and high exercise intensity. SDS-PAGE analysis and immunoblotting showed that, especially after exercise with high intensity, the concentrations of several other salivary proteins, including MUC7, albumin, and extra-parotid glycoprotein, also increased. ConclusionsExercise may not only lead to the anticipated increase in amylase and protein secretion, but also to an increase in salivary flow rate and MUC5B secretion.