Aerobic exercise training and vascular function with ageing in healthy men and women.

Cardiovascular diseases (CVD) remain the leading cause of morbidity and mortality in both men and women in developed societies. Age is the greatest risk factor for CVD due largely to adverse changes to arteries that include stiffening of the large elastic arteries (aortic and carotid arteries) and endothelial dysfunction. Vascular ageing is driven by oxidative stress, which reduces nitric oxide (NO) bioavailability and stimulates changes in the extracellular matrix. In women, reductions in circulating oestrogens with menopause interact with ageing processes to induce vascular dysfunction. Regular aerobic exercise is the most evidence-based strategy for reducing CVD risk with ageing in both men and women. Much of this cardiovascular-protective effect of aerobic exercise is likely due to its vascular health-enhancing influence. Large elastic artery stiffening with advancing age is attenuated in healthy adults engaged in aerobic exercise training, and aerobic exercise interventions improve arterial stiffness in previously sedentary middle-aged and older men and postmenopausal women. Regular aerobic exercise also enhances endothelial function with ageing in men (by reducing oxidative stress and preserving NO bioavailability), but not consistently in oestrogen-deficient postmenopausal women. In postmenopausal women, treatment with oestradiol appears to restore the ability of aerobic exercise to improve NO-mediated endothelial function by reducing oxidative stress. Several research gaps exist in our understanding of potential sex differences in the vascular adaptations to regular aerobic exercise. More information is needed on the factors that are responsible for sex differences, including the role of circulating oestrogens in transducing the aerobic exercise training 'stimulus'.

Case-Study Investigation of Equine Maternity via PCR-RFLP: A Biochemistry Laboratory Experiment.

A simple and robust biochemistry laboratory experiment is described that uses restriction fragment length polymorphism (RFLP) of polymerase chain reaction (PCR) products to verify the identity of a potentially valuable horse. During the first laboratory period, students purify DNA from equine samples and amplify two loci of mitochondrial DNA. During the second laboratory period, students digest PCR products with restriction enzymes and analyze the fragment sizes through agarose gel electrophoresis. An optional step of validating DNA extracts through realtime PCR can expand the experiment to three weeks. This experiment, which has an engaging and versatile scenario, provides students with exposure to key principles and techniques of molecular biology, bioinformatics, and evolution in a forensic context.

Inorganic Nitrite Supplementation Improves Endothelial Function With Aging: Translational Evidence for Suppression of Mitochondria-Derived Oxidative Stress.

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Short-term time-restricted feeding is safe and feasible in non-obese healthy midlife and older adults.

Chronic calorie restriction (CR) improves cardiovascular function and several other physiological markers of healthspan. However, CR is impractical in non-obese older humans due to potential loss of lean mass and bone density, poor adherence, and risk of malnutrition. Time-restricted feeding (TRF), which limits the daily feeding period without requiring a reduction in calorie intake, may be a promising alternative healthspan-extending strategy for midlife and older adults; however, there is limited evidence for its feasibility and efficacy in humans. We conducted a randomized, controlled pilot study to assess the safety, tolerability, and overall feasibility of short-term TRF (eating <8 h day-1 for 6 weeks) without weight loss in healthy non-obese midlife and older adults, while gaining initial insight into potential efficacy for improving cardiovascular function and other indicators of healthspan. TRF was safe and well-tolerated, associated with excellent adherence and reduced hunger, and did not influence lean mass, bone density, or nutrient intake. Cardiovascular function was not enhanced by short-term TRF in this healthy cohort, but functional (endurance) capacity and glucose tolerance were modestly improved. These results provide a foundation for conducting larger clinical studies of TRF in midlife and older adults, including trials with a longer treatment duration.