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Biomedical subjects

S B Manuck

Publications and source records attributed to S B Manuck.

At least 109 records · Page 6Linked to original sources
PubMed1983

Social stress and atherosclerosis in normocholesterolemic monkeys.

Socially stressed adult male cynomolgus monkeys (Macaca fascicularis) fed a low fat, low cholesterol diet developed more extensive coronary artery atherosclerosis than unstressed controls. Groups did not differ in serum lipids, blood pressure, serum glucose, or ponderosity. These results suggest that psychosocial factors may influence atherogenesis in the absence of elevated serum lipids. Psychosocial factors thus may help explain the presence of coronary artery disease (occasionally severe) in people with low or normal serum lipids and normal values for the other "traditional" risk factors.

Animals↗
PubMed1983

Social instability and coronary artery atherosclerosis in cynomolgus monkeys.

Epidemiologic research has increasingly implicated psychological factors in the emergence of atherosclerotic coronary heart disease in human beings. The study of behavioral influences on atherogenesis in man, however, is impeded by the difficulty of assessing coronary artery atherosclerosis in asymptomatic individuals and by the fact that significant arterial lesions typically develop only over relatively protracted intervals. Consequently, we have recently attempted development of an appropriate animal model for examining the atherogenic effects of psychosocial variables. In the first of two investigations, an experimental stressor--involving repeated reorganization of socially housed groups of adult, male cynomolgus monkeys (Macaca fascicularis) fed a moderately atherogenic diet--resulted in increased coronary artery atherosclerosis relative to control animals, though only among monkeys which retained dominant social status over the 22 months of the study. In the second investigation, which employed the same experimental procedures among monkeys fed a low cholesterol/low saturated fat diet, periodic social group reorganization similarly led to development of greater atherosclerosis in the coronary arteries. In neither experiment were psychosocial influences on coronary atherogenesis attributable to the concomitant effects of other physiologic variables commonly associated with atherosclerosis (e.g., serum lipids, blood pressure).

Aggression↗
PubMed1983

Behaviorally induced heart rate reactivity and atherosclerosis in cynomolgus monkeys.

It has been suggested that individual differences in behaviorally induced cardiovascular reactivity may mediate associations between behavioral factors and atherosclerotic disease. The present study provides data relevant to this hypothesis within an animal model. Experimental animals were 26 adult, male cynomolgus monkeys that had been fed a moderately atherogenic diet for 22 months. In the weeks preceding termination of these animals, monkeys were fitted with electrocardiogram (EKG) telemetry devices and their heart rates (HRs) recorded under baseline and stressed conditions. Stress-period HR measures were obtained during a standard challenge involving threatened capture and physical handling of the animals. At necropsy, the coronary arteries were subjected to pressure fixation and sections taken from the left main, left anterior descending, left circumflex, and right coronary arteries. Mean intimal area measurements, calculated for each artery, were then compared between animals identified as High (n = 8) and Low (n = 8) HR reactors during stress. Results indicated that High HR reactors had significantly greater coronary artery atherosclerosis than did Low HR reactive animals, both in individual arteries and on an overall coronary index. Atherosclerosis in the thoracic aorta was found to differ similarly between High and Low HR reactors. Additional analyses revealed that High HR reactors were significantly more aggressive, more ponderous, and had greater heart weights than did Low HR reactors. Although groups did not differ in resting HRs, body weights, or lipid values, high-density lipoprotein (HDL) cholesterol comprised a slightly smaller fraction of the total serum cholesterol of High, relative to Low, HR reactive monkeys. It is concluded that these findings provide initial support for the hypothesis that cardiovascular hyperresponsiveness under stress is related to the development of atherosclerosis.

Aggression↗
PubMed1982

Coronary-prone behavior pattern and cardiovascular response in persons with and without coronary heart disease.

The purpose of this investigation was to examine the psychophysiologic responses of Type A and Type B individuals, among persons with and without coronary heart disease (CHD). Subjects were 58 adult male volunteers; 24 had a history of myocardial infarction or clinically diagnosed angina pectoris (CHD) and 34 had been designated free of coronary disease following recent cardiologic examination (non-CHD). All subjects had normotensive resting blood pressures; among CHD patients, no subject was currently on beta-adrenergic blocking medication. Measures of heart rate (HR) and systolic and diastolic blood pressure (SBP, DBP) were obtained during a baseline period and while subjects performed a series of difficult and frustrating cognitive tasks. Each subject was also administered the Structured Interview for Type A--Type B assessment (SI) and the Jenkins Activity Survey (JAS). Results indicated that, independent of the A/B typology, CHD patients experienced significantly greater DBP elevations during the experimental tasks than did non-CHD controls. Type A subjects (as determined by the SI) exhibited greater task-related increases in SBP and DBP than did Type Bs, but changes in HR did not differ between these two groups. Type A--Type B assessments based on the JAS were unrelated to subjects SBP, DBP, or HR responses, and neither SI- nor JAS-defined Type As differed reliably from Type Bs on measures of task performance. Overall, these results are consistent with the hypothesis that heightened cardiovascular reactivity under stress may mediate relationships between behavioral factors and CHD.

Blood Pressure↗
PubMed1981

Stability of behaviorally induced heart-rate changes in children after one week.

Examining the stability of individual differences in behaviorally induced heart-rate reactivity in children, 34 boys having a mean age of 101.9 months were presented a cognitive task to perform "as rapidly and accurately as possible" at each of 2 experimental sessions scheduled 1 week apart, and recordings of heart rate were obtained during periods of rest and task performance on each occasion of testing. Task-related heart-rate reactivity across the 2 experimental sessions revealed substantial and highly reproducible individual differences, as evidenced (1) by subsets of subjects representing clearly differentiated groups of heart-rate reactors and non-reactors, and (2) by correlation of subjects' mean heart-rate responses between the first and second sessions. Individual differences in heart-rate reactivity were independent of subjects' task performance.

Child↗