Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 1 of 1
Full-Text Articles in Entire DC Network
Mri Measures Of Middle Cerebral Artery Diameter In Conscious Humans During Simulated Orthostasis., J M Serrador, P A Picot, B K Rutt, J K Shoemaker, R L Bondar
Mri Measures Of Middle Cerebral Artery Diameter In Conscious Humans During Simulated Orthostasis., J M Serrador, P A Picot, B K Rutt, J K Shoemaker, R L Bondar
Kinesiology Publications
BACKGROUND AND PURPOSE: The relationship between middle cerebral artery (MCA) flow velocity (CFV) and cerebral blood flow (CBF) is uncertain because of unknown vessel diameter response to physiological stimuli. The purpose of this study was to directly examine the effect of a simulated orthostatic stress (lower body negative pressure [LBNP]) as well as increased or decreased end-tidal carbon dioxide partial pressure (P(ET)CO(2)) on MCA diameter and CFV.
METHODS: Twelve subjects participated in a CO(2) manipulation protocol and/or an LBNP protocol. In the CO(2) manipulation protocol, subjects breathed room air (normocapnia) or 6% inspired CO(2) (hypercapnia), or they hyperventilated to approximately …