Universität zu Köln

Parganlija, Dajana, Gehlert, Sebastian ORCID: 0000-0001-6940-3084, Herrera, Frankyn, Rittweger, Joern, Bloch, Wilhelm and Zange, Jochen (2020). Enhanced Blood Supply Through Lower Body Negative Pressure During Slow-Paced, High Load Leg Press Exercise Alters the Response of Muscle AMPK and Circulating Angiogenic Factors. Front. Physiol., 11. LAUSANNE: FRONTIERS MEDIA SA. ISSN 1664-042X

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Abstract

Lower body negative pressure (LBNP) is an established method of simulating the gravitational effects of orthostasis on the cardiovascular system during space flight or at supine body position on Earth. We hypothesized that LBNP added onto leg press exercise would promote leg muscle perfusion, stimulate oxygen consumption, and modify acute molecular responses. Eighteen subjects performed fifteen slow-paced concentric (4 s) and eccentric contractions (4 s) without or with 40 mmHg LBNP. Force corresponding to 6% of the one-repetition maximum (1-RM) at knee flexion gradually increased to 60% 1-RM within the first half of the range of motion, thereafter remaining constant. AMPK and P-AMPK protein expression was determined in biopsies of vastus lateralis. Venous blood samples were used to measure angiogenic factors. Physiological responses to LBNP included an elevated EMG amplitude, higher heart rate and doubling of the cardiac output compared to control (p< 0.001). Muscle total hemoglobin was increased by around 20 mu mol/l vs. control (p< 0.001), accompanied by decreasing tissue oxygen saturation and elevated oxygen uptake (p< 0.05). MMP-2 levels were reduced, and the ratio of P-AMPK to AMPK elevated after exercise with LBNP (p< 0.05). MMP-9 similarly increased in both groups, whereas endostatin was only elevated in the control group (p< 0.05). Our results indicate facilitated peripheral blood supply and higher oxygen exploitation leading to activation of the energy sensor AMPK and differential regulation of angiogenic factors involved in muscle tissue remodeling and capillary growth. Simulating orthostasis with LBNP might promote beneficial structural adaptations of skeletal muscles during resistance exercise and contribute to future exercise countermeasures achieving increased muscle strength and endurance during space flight.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Parganlija, Dajana UNSPECIFIED UNSPECIFIED UNSPECIFIED Gehlert, Sebastian UNSPECIFIED orcid.org/0000-0001-6940-3084 UNSPECIFIED Herrera, Frankyn UNSPECIFIED UNSPECIFIED UNSPECIFIED Rittweger, Joern UNSPECIFIED UNSPECIFIED UNSPECIFIED Bloch, Wilhelm UNSPECIFIED UNSPECIFIED UNSPECIFIED Zange, Jochen UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-325450
DOI:	10.3389/fphys.2020.00781
Journal or Publication Title:	Front. Physiol.
Volume:	11
Date:	2020
Publisher:	FRONTIERS MEDIA SA
Place of Publication:	LAUSANNE
ISSN:	1664-042X
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language ACTIVATED PROTEIN-KINASE; HUMAN SKELETAL-MUSCLE; BED REST; MATRIX METALLOPROTEINASES; EXTRACELLULAR-MATRIX; PHOSPHORYLATION; COUNTERMEASURE; INTENSITY; SPACE; HYPERTROPHY Multiple languages Physiology Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/32545