Space Physiology
Head: Prof. Dr. med. Jörn Rittweger

Integrative Muscle Physiology



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The group “Integrative Muscle Physiology” works in the field of applied physiology and patho-physiology of human skeletal muscle. Muscle contractility, energy metabolism, perfusion and oxygen supply, as well as the electrical activity and the electro-mechanical coupling are examined. Exclusively non invasive methods are used.
A major point of interest is the examination of physiological mechanisms by which muscle adapts to permanent disuse or different kinds of muscle training. In an integrative physiological approach we study the interactions between muscle and the cardio-vascular system, and between muscle and bone.
Furthermore, we use non invasive methods for the diagnosis or therapy monitoring of patients with hereditary metabolic diseases of muscle and nervous system.

Weightlessness

Adaptations of muscle to microgravity or to simulation conditions inducing similar effects:

  • Pre- and post-flight examinations of astronauts and cosmonauts in the scope of the European-Russian missions to the former space Station MIR (EuroMir’94, ’95, ‘95E, and Mir’97).
  • Preparation of new experiments, which will be performed in the scope of future missions to the ISS or to Moon or Mars.
  • Examinations in the scope of bed-rest simulation studies.

Training and Countermeasures

Validation studies to test the effects of vibration or of fly-wheel inertial training on muscle growth and force-velocity performance in subjects with weakened muscles.
The training effects on normally active healthy subjects are compared with the effects on subjects, who have weakened muscle because of long-term immobilization or high age. In addition we study the potential benefits of adapted muscle training for patients with inborn muscle weakness.

Aims in the scope of spaceflight: The development and validation of an improved muscle training using less time per day to conserve the muscle mass and performance of astronauts during long term space missions, i.e. onboard the ISS or future flights to the planet Mars.

Muscle — Volume Regulation and Blood Circulation

During muscle work osmotic forces cause a water shift from the extracellular space (interstitium and blood vessels) into the intracellular space of the muscle fibres. Furthermore, especially leg muscles are frequently exposed to a volume change caused by changes in body position in the gravitational field (e.g. the transition from the horizontal lying to the upright standing position). We examine the effects of such volume changes on the ion balance and the consequences on muscle excitation, energy metabolism, contractility, and fatigue.

The increase in blood volume and flow during intensive exercise of large muscle groups is a major stimulus for an increase in cardiac output (pulse x stroke volume). All studies on immobilisation and training effects on muscle should also examine the system physiologic aspect of peripheral and central reactions of the cardio-vascular system (Cardiovascular- and Volume Regulation).

Muscle — Bone and Nutrion

The regulation mechanisms for growth and strength in muscle and bone cross at many points. All studies on immobilisation or training effects will also focus on the interference between muscle and bone in terms of mechanical forces, blood chemical parameters like growth hormones, and nutritional aspects (minerals, vitamins, protein, carbon hydrates, and fat) (Link: Ernährung und Knochenstoffwechsel)

Diagnosis and Therapy Control in Patients with Neurological Diseases

In close cooperation with the university clinics Bergmannsheil in Bochum a novel method was developed for the differential diagnosis of a group of hereditary muscle diseases each based on a specific genetically determined defect in one of the various enzymes involved in glycogen metabolism (muscle glycogenosis). Magnetic resonance spectroscopy and subsequent gene analysis replace the previously required analysis of muscle material that was received by surgery (biopsy).
A special benefit of the non-invasive methods offered by our muscle lab is the opportunity to perform repeated examinations without additional health risks. Such repetitions are required e.g. in therapy studies. In cooperation with neurological clinics in Bochum and Bonn we have performed various studies to test therapies for patients with inborn diseases of muscle or nervous system.

Description of the Muscle Lab

Current Partners:

  • European Astronaut Center (EAC) in Cologne
  • German Sports University Cologne: Institute for Training Science aud Sports Informatics, Institute for Physiology and Anatomy
  • Medical University Hannover, Institute of Sports Physiology and Sports Medicine
  • Ruhr-University-Bochum: University Clinic for Neurology, Clinics in Bergmannsheil, Bochum, University Clinic for Neurology, St. Josef Hospital, Bochum
  • University Bonn, Clinic for Neurolgy

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Cardiovascular- and Volume Regulation (http://www.dlr.de/me/en/desktopdefault.aspx/tabid-1935/2759_read-4226/usetemplate-print/)
Test Facilities (http://www.dlr.de/me/en/desktopdefault.aspx/tabid-1935/2759_read-4230/usetemplate-print/)