HETEROGENEITY IN NEUROENDOCRINE AND IMMUNE-RESPONSES TO BRIEF PSYCHOLOGICAL STRESSORS AS A FUNCTION OF AUTONOMIC CARDIAC ACTIVATION

Human responses to brief psychological stressors are characterized by changes and large individual differences in autonomic, neuroendocrine, and immune function. The authors examined the effects of brief psycho logical stressors on cardiovascular, neuroendocrine, and cellular immu ne response in 22 older women to investigate the common effects of str ess across systems. They also used interindividual variation in heart rate reactivity, cardiac sympathetic reactivity (as indexed by preejec tion period reactivity in their reactivity paradigm), and cardiac vaga l reactivity (as indexed by respiratory sinus arrhythmia reactivity) t o explore the heterogeneity in human responses to brief psychological stressors. The results revealed that brief psychological stressors hei ghtened cardiac activation, elevated plasma catecholamine concentratio ns, and affected the cellular immune response. It was also found that individuals characterized by high, relative to low, cardiac sympatheti c reactivity showed higher stress-related changes in adrenocorticotrop ic hormone and cortisol plasma levels but comparable changes in epinep hrine and norepinephrine concentrations, These data suggest that the e ffects of psychological stressors on cardiovascular and cellular immun e response are governed by coordinated regulatory mechanism(s) and tha t going beyond the simple notion of heart rate reactivity to examine n eural substrates may shed light on the interrelationships among and th e regulatory mechanisms for the autonomic, endocrine, and immune respo nses to stressors.