Dr Hans Degens

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Academic Interests

• The main academic interest is age-related changes in skeletal muscle morphology and function. Thereto we apply single skinned muscles fibres from human muscle biopsies and rodents. The use of single skinned muscle fibres allows one to determine changes in cross-bridge kinetics and fibre function without bias that can be introduced in vivo by e.g. changes in neural drive.Muscle is highly adaptive and resistance (including overload model in rats) and endurance training are used to assess changes in muscle (fibre) function and morphology. Recently we have also explored how hypoxia does affect the muscle, as not only mountaineers, but also patients with chronic diseases as heart failure and chronic obstructive pulmonary disease and elderly people, may suffer from hypoxia. Of interest is how the muscle adapts to maintain an adequate oxygenation during hypoxia and hypertrophy. The latter is of interest as an increase in fibre size may increase the diffusion distances from the capillaries to the interior of the muscle cell. In smokers this may be aggravated by the presence of carboxyhaemoglobin that not only reduces the oxygen carrying capacity in the blood but also the release of oxygen in the muscle due to the left-shift of the haemoglobin dissociation curve. The impact of smoking and smoking cessation on muscle function is an area of continuing interest.

Teaching Specialisms

• Skeletal muscle physiology

Professional Highlights

• 1992: Award for outstanding Achievements in the field of Oxygen Transport to Tissue for young investigators2002-2003: A series of studies showing impaired muscle hypertrophy in response to overload in old rats. We were the first to show a potential role of changes in inhibitor of differentiation proteins (Id) and myogenic regulatory factors in the attenuated hypertrophic response at old age2005: The first to use electrically evoked contraction in patients with COPD showing no decrease in muscle fatigue resistance, in contrast to many previous observations.2007-8: Several papers showing that smoking reduces muscle fatigue resistance, probably partly via carbon monoxide2007-2011: Several papers showing that even with a most comprehensive approach hitherto to determine muscle size and force generating capacity the specific tension appears to be elevated after resistance exercise in humans2010-11 Several papers providing some mechanistic insight in the variability of function of fibres of the same type and how this may be modified by oxidative stress and chronic (in contrast to acute) hypoxia.

Recent External Roles

• 2004-2005 Consultant Dept Physiology Radboud University Nijmegen The Netherlands2007-2009 Consultant Current Biodata2011-present Consultant German Aerospace Institute, Cologne2010-present Part of the International Osteoporosis Foundation Nutrition an Sarcopaenia Working Group

Professional Activities

• Research and Teaching

Research Interests

• See academic interests

Recent Publications

Degens H. The role of systemic inflammation in age-related muscle weakness and wasting. Scand J Med Sci Sports 20, 28-38, 2010 (IF 2008: 2.809).

Erskine RM, Jones DA, Williams AG, Stewart CE, Degens H. Resistance training increases in vivo quadriceps femoris muscle specific tension in young men. Acta Physiol, 199, 83-89, 2010 (IF 2008 2.455).

Wüst RCI, Winwood K, Wilks DC, Morse CI, Degens H, Rittweger J. Effects of smoking on tibial and radial bone mass and strength may diminish with age. J Clin Endocr Metabolism, 95, 2763-2771, 2010 (IF 2008 6.325).

Rittweger J, Moss AD, Colier W, Stewart C, Degens H. Muscle tissue oxygenation and VEGF in VO2-matched vibration and squatting exercise. Clin Physiol Funct Imaging, 30, 269-278, 2010 (IF 2009: 1.333).

Goosey-Tolfrey V, Foden E, C Perrett, Degens H. Effects of inspiratory muscle training on respiratory function and repetitive sprint performance in wheelchair basketball players. Brit J Sport Med, 44, 665-668, 2010 (IF 2009: 2.547)

McPhee JS, Williams AG, Degens H, Jones DA. Inter-individual variability in the adaptation of leg muscles following a standardised endurance training programme in young women. Eur J Appl Physiol,109, 1111-1118, 2010 (IF2009 2.047).

Rauch F, Sievanen H, Boonen S, Cardinale M, Degens H, Felsenberg D, Roth J, Schoenau E, Verschueren S, Rittweger J. Reporting Whole-body Vibration intervention studies: Recommendations of the International Society of Musculoskeletal and Neuronal Interactions. J Musculoskel Neuron Int, in 10, 193-198, 2010.

Degens H, Alessandra B, Gilliver SF, Slevin M, van Heijst A, Wüst RCI. Changes in contractile properties of skinned single rat soleus and diaphragm fibres after chronic hypoxia. Pflügers Archiv, 460, 863-873, 2010 (IF 2009 3.695).

Erskine RM, Jones DA, Stewart CE, Williams AG, Degens H. Inter-individual variability in the adaptation of human muscle specific tension to progressive resistance training. Eur J Appl Physiol, 110, 1117-1125, 2010 (IF2009 2.047).

Degens H, Rittweger J. What is new in musculoskeletal interactions – Muscle oxygenation, myonuclear domain, acupuncture, titin and phosphate. J Musculoskel Neuron Int, 10, 245-248, 2010.

Gilliver SF, Jones DA, Rittweger J, Degens H. Effects of oxidation on the power of chemically skinned rat soleus fibres. J Musculoskel Neuron Int, 10, 267-273, 2010.

Arampatzis A, Degens H, Baltzopoulos V, Rittweger J. Why do older sprinters reach the finish line later? Exerc Sport Sci Rev. 39, 18-22, 2011. (IF 2009: 3.228)

van der Meer SFT, Jaspers RT, Jones DA, Degens H. The time course of myonuclear accretion during hypertrophy in young-adult and old rat plantaris muscle. Ann. Anat., 193, 56-63, 2011. (IF 2009: 0.877)

van der Meer SFT, Jaspers RT, Jones DA, Degens H. The time course of changes in the myonuclear domain during denervation in young-adult and old rat gastrocnemius muscle. Muscle & Nerve, 43, 212-222, 2011 (IF 2009 2.287).

Erskine RM, Jones DA, Maffulli N, Williams AG, Stewart CE, Degens H. What causes in vivo muscle specific tension to increase following resistance training? Exp. Physiol., 96, 145-155, 2011 (IF 2009: 3.168)

Gilliver SF, Degens H, Rittweger J, Jones DA. Effects of submaximal activation on the determinants of power of chemically skinned rat soleus fibres. Exp. Physiol., 96, 171-178, 2011 (IF 2009: 3.168)

de Jong WM, Degens H. Evolutionary dynamics of digital and nucleotide codes: a mutation protection perspective. The Open Evol. J., 5, 1-4, 2011.

Gilliver SF, Jones DA, Rittweger J, Degens H. Variation in the determinants of power of chemically skinned type I rat soleus muscle fibres. J Comp Physiol A, 197, 311-319, 2011 (IF 2009: 1.852).

Testerink J, Degens H, Rittweger J, Shiraishi A, Jaspers RT, de Haan A. Effects of alfacalcidol on the contractile properties of the gastrocnemius medialis muscle in adult and old rats. J Physiol Pharmacol, 62, 111-118,2011