CHANGE OF SECRETORY IMMUNOGLOBULIN A AND CARDIOVASCULAR ACTIVITY AS A FUNCTION OF DURATION TIME OF MENTAL ARITHMETIC TASK
 
Tsuge, H. and Ohira, H., Nagoya University, Japan
 
A number of studies have shown that secretion rate of secretory immunoglobulin A (sIgA) in saliva increases in response to acute stress laboratory tasks (Ohira, 2000; Willemsen et al., 1999). However, the mechanism(s) underlying these short-term increase in salivary sIgA has yet to be determined. The role of autonomic nervous system in salivary sIgA responses to laboratory stressor was explored in the present study in which volume of salivary sIgA and cardiovascular activity were recorded at rest and at mental arithmetic tasks. These tasks were mental arithmetic tasks with 5 conditions of duration time, 5 min, 10 min, 20 min, and 30 min and a no-task control condition. We measured volume of salivary sIgA, heart rate and psychological indexes at some points before and after the tasks. Five male and five female were subjected to 4 stress and control conditions. The order of conditions was counterbalanced across participants and each condition was on a separate day. Mental arithmetic task increased salivary sIgA concentration and heart rate expect for 5min task, and duration of the tasks affected recovery of salivary sIgA concentration and heart rate. Namely, recovery of salivary sIgA concentration the more delayed in task with the more duration. The present study explored for the first time temporal function of response of sIgA to acute stressor.