Absence of enhanced sympathoadrenal activity and behaviorally evoked cardiovascular reactivity among offspring of hypertensives.

To determine whether offspring of hypertensives show enhanced sympathetic nervous system activity, we evaluated several indices of sympathoadrenal activation and cardiovascular responsiveness to behavioral stimuli among 90 normotensive, young adult men having either one or two hypertensive parents (PH+(-), PH++) or normotensive parents only (PH--) (n = 30/group). Measurements included heart rate (HR) and blood pressure (BP) reactions to three mental stressors (the Stroop test, mental arithmetic, mirror tracing), a cold pressor test, postural adjustment (60 degrees upright tilt), isometric exercise and bicycle ergometry, as well as the 24-h excretion of catecholamines (epinephrine [E], norepinephrine [NE]) and venous plasma catecholamine concentrations, both at rest (seated and supine) and in response to the Stroop test and upright tilt. The three groups did not differ in age, education, body mass index (BMI), estimated aerobic fitness, resting HR, cardiac preejection period (PEP) and PEP:LVET (left ventricular ejection time) ratio, 24-h Na or K excretion, or fasting lipids, insulin or plasma renin activity.

Blood platelet responsivity to acute mental stress.

To evaluate the effects of mental stress on blood platelet activity, platelet secretion and aggregation were measured in 40 healthy young men, assigned in a 3:1 ratio to an experimental and control condition. After a baseline period, experimental subjects participated in a 21-minute, frustrating computer task (the Stroop test), while control subjects remained seated quietly for the same duration. Blood was drawn from all subjects immediately before and after the task period for assessment of platelet activity (secretion of ATP and aggregation in response to 5 and 20 microM ADP).

Lymphocyte subset and cellular immune responses to a brief experimental stressor.

To evaluate effects of acute mental stress on aspects of cellular immunity, lymphocyte populations and phytohemagglutinin (PHA)-stimulated T-cell mitogenesis were measured in 33 healthy young men, both before and immediately following subjects' performance of a frustrating, 21-minute laboratory task (Stroop test). Relative to baseline evaluations, post-task measurements showed a significant reduction in mitogenesis and alterations in various circulating lymphocyte populations; the latter included a diminished T-helper/T-suppressor cell ratio and an elevation in the number of natural killer cells. Eleven subjects assigned to a control (unstressed) condition exhibited no changes in lymphocyte populations, but did show an increase in T-cell proliferation, compared with pretask measurements.

Individual differences in behaviorally evoked cardiovascular response: temporal stability and hemodynamic patterning.

This study evaluates the reproducibility of individual differences in behaviorally evoked cardiovascular reactivity among 39 young adult males. Presented also are initial data describing idiosyncratic patterns of hemodynamic adjustment that may underlie pressor responses to laboratory stressors. Subjects were administered three experimental stressors (mental arithmetic, mirror tracing, and bicycle exercise) on two occasions, four weeks apart.

Marital discord and immunity in males.

While limited data suggest significant gender differences in mental and physical health risks following marital disruption, men have not been studied as intensively as women. In this study, self-report data and blood samples were obtained from 32 separated or divorced men and 32 sociodemographically matched married men. Separated/divorced men were more distressed and lonelier, and reported significantly more recent illness than did married men; the former also had significantly poorer values on two functional indices of immunity (antibody titers to two herpesviruses), while not differing significantly on quantitative indices (percentages of helper and suppressor cells and their ratio).