MADRID, November 11 (EUROPE PRESS) –
Regular exercise protects the cardiovascular system by reducing risk factors such as cholesterol and blood pressure. "But we believe there are some risk factors for cardiovascular disease that are not fully understood," admits Matthias Nahrendorf of the Center for Systems Biology at Massachusetts General Hospital (MGH), in an article published in the journal & # 39; Nature Medicine & # 39 ;.
In particular, Nahrendorf and his team wanted to better understand the role of chronic inflammation, which contributes to the formation of blockages that clog arteries called plaque.
The researchers investigated how physical activity affects bone marrow activity, especially hematopoietic stem and progenitor cells (HSPC), which can become all types of blood cells, including white blood cells called leukocytes, which promote inflammation.
The body needs leukocytes to defend against infections and eliminate foreign bodies, "but when these cells become too envious, they begin to swell in places where they should not, including the walls of the arteries," explains Nahrendorf.
Nahrendorf and his colleagues studied a group of laboratory mice housed in cages with treadmills. Some of the mice ran up to one kilometer per night on the spinning wheels.
Mice in a second group were kept in cages without treadmills. After six weeks, the running mice had significantly reduced HSPC activity and lower levels of inflammatory leukocytes than other mice that simply sat around their cages throughout the day.
Nahrendorf explains that exercise allowed mice to produce less leptin, a hormone produced by adipose tissue that helps control appetite, but also indicates that HSPCs become more active and increase leukocyte production. In two large studies, the team detected high levels of leptin and leukocytes in sedentary people who have cardiovascular disease related to chronic inflammation.
"This study identifies a new molecular link between exercise and inflammation that takes place in the bone marrow and highlights a previously under-appreciated role of leptin in exercise-mediated cardiovascular protection," explains Michelle Olive, program director at the Division of Cardiovascular Sciences of the National Heart, Lung and Blood Institute.
"This work adds a new piece to the puzzle of how sedentary lifestyles affect cardiovascular health and emphasizes the importance of following physical activity patterns," he adds.
The study found that decreasing leukocyte levels through exercise did not make running mice susceptible to infection.
This study emphasizes the importance of regular physical activity, but focuses more on how exercise suppresses inflammation can lead to new strategies to prevent heart attacks and strokes. "We hope this research will lead to new therapies that treat cardiovascular disease from a whole new angle," concludes Nahrendorf.