23 July 2015

Age increases the endurance of blood vessels

Despite the fact that the causes of most age-related diseases are unclear, oxidative stress is considered the most important of the mechanisms involved. Oxidative stress is associated with cardiovascular and neurodegenerative diseases, including diabetes mellitus, hypertension and malignant tumors developing in old age. However, researchers at the University of Missouri, working under the guidance of Professor Steven Segal, have recently found that in fact aging provides pronounced protection against oxidative stress. The data they obtained suggest that aging can trigger an adaptive reaction that neutralizes the effect of oxidative stress on blood vessels.

According to Professor Segal, molecules known as reactive oxygen species (ROS) play an important role in the regulation of cellular functions. However, their excessive production can contribute to the development of so-called oxidative stress, which can disrupt various functions of cells, including their growth and division.

In order to understand the influence of the aging process on the functioning of blood vessels exposed to oxidative stress, the authors studied the state of the endothelium (inner shell) of small resistive arteries – a kind of "taps" at the border of central and peripheral circulation, which play an important role in maintaining cardiac function, since they regulate the amount of blood entering the tissues, and systemic blood pressure. 

As part of the study, the state of the endothelium of the resistive arteries of male mice aged 4 and 24 months was analyzed in vitro, which, in terms of human age, corresponds to approximately 20-23 and 54-56 years. First, the authors studied the state of the endothelium at rest and in the absence of oxidative stress, after which they induced oxidative stress by adding hydrogen peroxide. When exposed to oxidative stress for 20 minutes, an abnormal increase in the level of calcium ions occurred in the endothelial cells of young animals, which was not observed in the cells of mice of "pre-retirement" age. This observation is very important, since it is known that an excessive increase in the concentration of calcium ions can cause serious damage to cells.

When the period of stress exposure was extended to 60 minutes, 7 times more cells died in the endothelium of young animals than in the endothelium of the elderly. This indicates that with age, the endothelium adapts and acquires the ability to maintain cell integrity under conditions of oxidative stress.

According to the authors, the results obtained were very unexpected, as they contradict traditional ideas according to which the aging process is accompanied by a violation of the functional integrity of the endothelium. Despite the fact that further research is needed to clarify the underlying mechanisms of this phenomenon, the data obtained demonstrate the existence of a natural tendency to adapt the body to oxidative stress during healthy aging.

Article by Matthew J. Socha et al. Advanced Age Protects Microvascular Endothelium from Aberrant Ca2+ Flux and Cell Death Induced by Hydrogen Peroxide is published in the Journal of Physiology.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the University of Missouri: Blood Vessels Can Actually Get Better With Age.

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