Physical activity and atherosclerosis in the adult chicken

The effects of vasectomy and exercise on cholesterol levels in rat aortas

The effects of vasectomy and exercise upon esterified, unesterified and total cholesterol in rat aortic tissue was determined. A factorial design with two activity levels (aerobic exercise, sedentary) and three treatments (vasectomy, sham-vasectomy, control) was employed. Vasectomy significantly increased the amount of esterified and total cholesterol in aortic tissue. The vasectomy sedentary group had significantly higher unesterified cholesterol levels than the three exercise groups. Total cholesterol levels were significantly higher for the sedentary groups than the exercise groups. There was no significant difference between exercise and sedentary groups in esterified cholesterol.

Effect of exercise on aortic atherosclerosis and other cardiovascular variables among hyper- and hypotensive turkeys

Two experiments were conducted to determine the effects of physical training on the turkey cardiovascular system. Sexually mature (Experiment 1) and immature (Experiment 2) Large White turkeys were used. Equal numbers of genetically hypertensive and hypotensive birds were used in each experiment. In each experimental group, birds were randomly divided into exercise and control treatments. Assessments were made with regard to training effects and differences associated with genetic blood pressure strain. Exercise had no significant effect on the severity of atherosclerosis or serum lipid levels in either experiment. Significantly greater hematocrits were recorded among birds exercised in Experiment 1; however, hemoglobin concentration did not follow this trend. Exercise was also associated with increased cardiac dimensions (Experiment 1) and increased body weight (Experiment 2). Genetic hypertension was associated with accelerated atherogenesis and higher serum cholesterol levels in immature birds, and in mature birds cardiac enlargement was associated with hypertension. Differences in behavior response to exercise were observed between the two experiments. Sexually mature hypertensive turkeys showed less endurance to the walking regimen than the hypotensive turkeys, but no such differences were observed in immature hypertensive or hypotensive birds.

Reduction of coronary atherosclerosis by moderate conditioning exercise in monkeys on an atherogenic diet

All available evidence that exercise may protect against coronary heart disease is circumstantial, and direct evidence is difficult to obtain in human beings. Therefore, we studied the effect of moderate conditioning with treadmill exercise on developing coronary-artery disease in monkeys on an atherogenic diet. Physical training was demonstrated by slow heart rates. Serum total cholesterol was the same (approximately 600 mg per deciliter or 15.5 mmol per liter) in exercising and non-exercising monkeys, with significantly higher high-density-lipoprotein (HDL) cholesterol and much lower triglyceride and low-density-lipoprotein (LDL) plus very-low-density-lipoprotein (VLDL) triglyceride in the exercise group. Ischemic electrocardiographic changes, angiographic signs of coronary-artery narrowing, and sudden death were observed only in non-conditioned monkeys, in which post-mortem examination revealed marked coronary atherosclerosis and stenoses. Exercise was associated with substantially reduced overall atherosclerotic involvement, lesion size, and collagen accumulation; it also produced much larger hearts and wider coronary arteries, further reducing the degree of luminal narrowing. Our data suggest that moderate exercise may prevent or retard coronary heart disease in primates.

Physical fitness and coronary heart disease. Some basic views

The purposes of a physical training program are examined and the evidence for the general and circulatory benefits of physical fitness is discussed. While the proof of benefits is not established, there is sufficient evidence from current studies to justify encouragement of the exercise programs. The evidence that exercise lessens experimental atherogenesis is equivocal. The possibility that physical fitness alters the morbidity and mortality of coronary sclerosis remains conjectural. Whether a physical fitness program would (1) lessen the incidence of intravascular thrombosis or atheromatous ulceration, (2) increase the extent or rate of development of coronary collaterals in man although the evidence in animals is suggestive, (3) improve the performance capacity of the heart, (4) decrease the likelihood of arrhythmias, or (5) result in more efficient bodily responses to the stresses associated with myocardial infarction is not clear or has not been definitely ascertained because of lack of evidence.