title: Effects of exercise intensity on salivary antimicrobial proteins and markers of stress in active men.
abstract: In the present study, we assessed the effects of exercise intensity on salivary immunoglobulin A (s-IgA) and salivary lysozyme (s-Lys) and examined how these responses were associated with salivary markers of adrenal activation. Using a randomized design, 10 healthy active men participated in three experimental cycling trials: 50% maximal oxygen uptake (VO2max), 75%VO2max, and an incremental test to exhaustion. The durations of the trials were the same as for a preliminary incremental test to exhaustion (22.3 min, sx = 0.8). Timed, unstimulated saliva samples were collected before exercise, immediately after exercise, and 1 h after exercise. In the incremental exhaustion trial, the secretion rates of both s-IgA and s-Lys were increased. An increase in s-Lys secretion rate was also observed at 75%VO2max. No significant changes in saliva flow rate were observed in any trial. Cycling at 75%VOmax and to exhaustion increased the secretion of alpha-amylase and chromogranin A immediately after exercise; higher cortisol values at 75%VO2max and in the incremental exhaustion trial compared with 50%VO2max were observed 1 h immediately after exercise only. These findings suggest that short-duration, high-intensity exercise increases the secretion rate of s-IgA and s-Lys despite no change in the saliva flow rate. These effects appear to be associated with changes in sympathetic activity and not the hypothalamic - pituitary - adrenal axis.
authors.affiliation: School of Sport and Exercise Sciences, Loughborough University, Loughborough, UK. judithallgrove@hotmail.co.uk
authors.forename: Judith E
authors.initials: JE
authors.lastname: Allgrove
authors.forename: Elisa
authors.initials: E
authors.lastname: Gomes
authors.forename: John
authors.initials: J
authors.lastname: Hough
authors.forename: Michael
authors.initials: M
authors.lastname: Gleeson
mesh_terms: D000328:Adult; D053379:Chromogranin A / Q000378:metabolism*; D015331:Cohort Studies; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism*; D008297:Male; D009113:Muramidase / Q000378:metabolism*; D012463:Saliva / Q000737:chemistry / Q000378:metabolism*
chemical_list: D053379:Chromogranin A; D007070:Immunoglobulin A; D009113:Muramidase