PhD defence - Michael Permin Nyberg

Michael Permin Nyberg is defending his PhD thesis

Vascular function and regulation of blood flow in resting and contracting skeletal muscle

Insight from essential hypertension, aging, and physical activity


8 July 2013 at 14:00


Auditorium 1, August Krogh building, Universitetsparken 13, Copenhagen


Professor Jørgen Wojtaszewski (Chair), Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark

Professor Jose Calbet, University of Las Palmas de Gran Canaria, Department of Physical Education, Canary Islands, Spain

Professor Phil Clifford, Anesthesia Research 151, Zablocki Veterans Affairs Medical Center, Milwaukee, USA


Professor Ylva Hellsten, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark

About the thesis

The precise matching of blood flow, oxygen delivery and metabolism is essential as it ensures that any increase in muscle work is precisely matched by increases in oxygen delivery. Therefore, understanding the control mechanisms of skeletal muscle blood flow regulation is of great biological importance.

The present work provides new insight in to vasodilator interactions important for exercise hyperemia and sheds light on mechanisms important for vascular function and regulation of skeletal muscle blood flow in essential hypertension (high blood pressure) and aging and identifies mechanisms by which physical activity affects the function of the vascular network.


The vasodilators ATP and adenosine stimulate the nitric oxide and prostanoid systems in skeletal muscle. These vasodilator interactions may, at least in part, explain the central role of nitric oxide and prostanoids in the regulation of exercise hyperemia. Furthermore, blood flow to contracting leg skeletal muscles is reduced both in essential hypertension and with aging.

The potential difference in vasoactive system(s) responsible for the reduction in blood flow in the two conditions is in agreement with the suggestion that no single compound can explain exercise hyperemia and indicates that any condition associated with reduced oxygen delivery needs to be investigated independently. Physical activity can attenuate or even counteract the effects of essential hypertension and aging on vascular function and exercise hyperemia.

2013, 99 pages, ISBN 978 87 7611 610 1