Ohira, H., Nagoya University, Niimi, M., Tokai Women's College and Watanabe, Y., Gifu Prefecture Institute of Health and Environment, Japan
Studies in psychoneuroimmunology have shown that chronic and brief stressors influence many aspects of human immune systems. Secretory immunoglobulin A (s-IgA) is the predominant antibody thought to be a first line defense against invading organisms in local mucosal sites. It has been known that acute or brief experimental stressors transiently increase secretion of s-IgA. Though mechanism of the phenomena is not fully clarified, s-IgA has been thought as a useful index of stress reaction. The present study examined buffering effects social support to stress responses by measuring salivary s-IgA and state anxiety (STAI). Twenty-four female undergraduates made a speech in front of audience as a brief stress task. A third of them were provided emotional social support, another third of them were provided informational social support, and the rest was served as a control group without social support. Volume of s-IgA in the control group elevated during waiting for the speech and just after the speech compared to baseline suggesting that the speech task evoked enhancement of secretory immune function. On the other hand, the subjects in the emotional social support group showed increased s-IgA during waiting period but suppressed s- IgA after the speech task. Volume of s-IgA in the informational social support group was unchanged at any points. However scores of state anxiety identically increased in all groups during waiting period. These results suggest that social support attenuates impact of stressor to somatic state even out of awareness.