Universität zu Köln

Marshall-Goebel, Karina ORCID: 0000-0002-5240-7625, Ambarki, Khalid, Eklund, Anders ORCID: 0000-0002-2031-722X, Malm, Jan ORCID: 0000-0001-6451-1940, Mulder, Edwin, Gerlach, Darius ORCID: 0000-0001-7044-6065, Bershad, Eric ORCID: 0000-0003-4091-2031 and Rittweger, Joern (2016). Effects of short-term exposure to head-down tilt on cerebral hemodynamics: a prospective evaluation of a spaceflight analog using phase-contrast MRI. J. Appl. Physiol., 120 (12). S. 1466 - 1474. BETHESDA: AMER PHYSIOLOGICAL SOC. ISSN 1522-1601

Full text not available from this repository.

Abstract

Alterations in cerebral hemodynamics in microgravity are hypothesized to occur during spaceflight and could be linked to the Visual Impairment and Intracranial Pressure syndrome. Head-down tilt (HDT) is frequently used as a ground-based analog to simulate cephalad fluid shifts in microgravity; however, its effects on cerebral hemodynamics have not been well studied with MRI techniques. Here, we evaluate the effects of 1) various HDT angles on cerebral arterial and venous hemodynamics; and 2) exposure to 1% CO2 during an intermediate HDT angle (-12 degrees) as an additional space-related environmental factor. Blood flow, cross-sectional area (CSA), and blood flow velocity were measured with phase-contrast MRI in the internal jugular veins, as well as the vertebral and internal carotid arteries. Nine healthy male subjects were measured at baseline (supine, 0 degrees) and after 4.5 h of HDT at -6 degrees, -12 degrees (with and without 1% CO2), and -18 degrees. We found a decrease in total arterial blood flow from baseline during all angles of HDT. On the venous side, CSA increased with HDT, and outflow decreased during -12 degrees HDT (P = 0.039). Moreover, the addition of 1% CO2 to -12 degrees HDT caused an increase in total arterial blood flow (P = 0.016) and jugular venous outflow (P = 0.001) compared with -12 degrees HDT with ambient atmosphere. Overall, the results indicate decreased cerebral blood flow during HDT, which may have implications for microgravity-induced cerebral hemodynamic changes.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Marshall-Goebel, Karina UNSPECIFIED orcid.org/0000-0002-5240-7625 UNSPECIFIED Ambarki, Khalid UNSPECIFIED UNSPECIFIED UNSPECIFIED Eklund, Anders UNSPECIFIED orcid.org/0000-0002-2031-722X UNSPECIFIED Malm, Jan UNSPECIFIED orcid.org/0000-0001-6451-1940 UNSPECIFIED Mulder, Edwin UNSPECIFIED UNSPECIFIED UNSPECIFIED Gerlach, Darius UNSPECIFIED orcid.org/0000-0001-7044-6065 UNSPECIFIED Bershad, Eric UNSPECIFIED orcid.org/0000-0003-4091-2031 UNSPECIFIED Rittweger, Joern UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-272206
DOI:	10.1152/japplphysiol.00841.2015
Journal or Publication Title:	J. Appl. Physiol.
Volume:	120
Number:	12
Page Range:	S. 1466 - 1474
Date:	2016
Publisher:	AMER PHYSIOLOGICAL SOC
Place of Publication:	BETHESDA
ISSN:	1522-1601
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language LONG-DURATION SPACEFLIGHT; BLOOD-FLOW VELOCITY; CO2 REACTIVITY; CARBON-DIOXIDE; THIGH CUFFS; SPACE; PRESSURE; ADAPTATION; ARTERIAL; AUTOREGULATION Multiple languages Physiology; Sport Sciences Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/27220