Thesis-2007-Allgrove.pdf (3.68 MB)
Factors influencing the mucosal immune response to exercise
thesis
posted on 2013-05-21, 16:06 authored by Judith E. AllgroveDespite the abundance of research conducted into the effects of exercise on mucosal
immunity the results remain controversial. Much of the inconsistencies arise from the
exercise protocols, the participants studied and their nutritional status, as well as
methodological and analytical differences. The purpose of this thesis was to examine the
influence of some of these factors, and to investigate potential means of enhancing the
mucosal immune response to exercise. In study 1 (Chapter 3) it was shown that a fed or
fasted state 2 h prior to exercise had no effect on the s-IgA concentration or secretion rate
during prolonged exercise. However, when participants were fed during exercise (Chapter 4),
the secretion rate of salivary antimicrobial proteins lysozyme and a-amylase increased, but sIgA
remained unchanged. These changes were likely due to the activation of mechanical and
gustatory receptors leading to a reflex stimulation of protein secretion via the autonomic
nerves, rather than changes in stress hOnliones, since cortisol did not change significantly
during exercise. Study 3 (Chapter 5) extended these findings where it was demonstrated that
chewing flavoured gum during exercise enhanced lysozyme and a-amylase secretion but
resulted in a small reduction in s-IgA secretion rate. Salivary antimicrobial proteins are
affected by the exercise intensity since both s-IgA and lysozyme secretion rate increased
post -exercise following an incremental test to exhaustion, but not after exercise at 50%
Y02max. Moreover, lysozyme secretion rate was also elevated following exercise at 75%
Y02mru<, whereas s-IgA remained unchanged. These effects are thought to be mediated by
increased sympathetic nervous system activity reflected by the concomitant increases in (lamylase
and chromogranin A, rather than the hypothalamic-pituitary-adrenal axis. Resting
mucosal immunity exhibits significant gender differences. In study 1 (Chapter 3) s-IgA
concentration, secretion rate and osmolality were found to be lower in females than in males
at rest. In addition, saliva flow rate was found to be lower in females compared with males in
study 5 (Chapter 7). However, these differences did not appear to influence the salivary
responses to acute exercise or exercise training. Chronic exercise training in elite male and
female swimmers resulted in lower levels of s-IgA secretion rate following periods of intense
training prior to competition compared with post-competition (Chapter 7), but these levels
were not directly associated with reported episodes of respiratory illness.
History
School
- Sport, Exercise and Health Sciences
Publisher
© Judith AllgrovePublication date
2007Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough UniversityEThOS Persistent ID
uk.bl.ethos.504106Language
- en