Exercise and Salivary IgA Response
摘要
Salivary IgA (sIgA) has been used to be a key indicator in determining the effect of different forms of stress on mucosal immunity. This review was focused to discuss the following topics: (1) the modulation of sIgA secretion; (2) sIgA and exercise-induced upper respiratory tract infection (URTI); (3) sIgA response and exercise; (4) nutritional supplementation and exercise-induced sIgA responses; (5) repeated bouts of exercise and sIgA responses. Summaries were concluded in this review according to the current knowledge of the sIgA responses to exercise: (1) sIgA secretion and functions are regulated both by the stimulation of sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal-(HPA)-axis; (2) activated SNS and/or HPA induced by exercise might decrease saliva flow rate immediately and inhibit sIgA secretion and antigen-specific IgA production chronically; (3) the lower levels of sIgA may compromise immunity in mucosal surfaces and stresses induced by training and/or competition would temporarily impair oral immunity, placing elite athletes at a higher risk of URTI within 2 weeks after exercise; (4) the ingestion of carbohydrate and vitamin C appeared not to affect sIgA response following prolonged exercise; (5) the different times of day did not influence sIgA response to exercise; (6) the second exercise bout did not appear to further compromise the oral immunity compared with the first identical exercise bout and carbohydrate ingestion during any period of two repeated prolonged exercise bouts did not to induce different effects on oral immunity compared with placebo trials.