HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Arbeille, P. P. Articles by Mohty, D. M. Search for Related Content PubMed PubMed Citation Articles by Arbeille, P. P. Articles by Mohty, D. M.

Portal vein cross-sectional area and flow and orthostatic tolerance: a 90-day bed rest study.

Unité Médecine et Physiologie Spatiale, Departement de Médecine Nucléaire et Ultrasons, Centres Hospitaliers Universitaires Trousseau, 37044 Tours, France

Submitted 22 March 2005 ; accepted in final form 11 July 2005

The objective of this study was to evaluate the changes in the portal vein cross-sectional area (PV CSA) and flow during a stand test associated with orthostatic intolerance. Eighteen subjects underwent a 90-day head-down tilt (HDT) bed rest at 6°: 9 controls (Con) and 9 with flywheel exercise countermeasures (CM). At post-HDT, nine subjects (5 CM, 4 Con) were tolerant, and nine were intolerant. The PV CSA was measured by echography. We found that at HDT day 85, the PV CSA at rest had increased less in the CM subjects than in the Con (+12 vs. +27% from pre-HDT supine; P < 0.05), whereas it increased similarly in tolerant and intolerant subjects (23 and 16%, respectively). Two days after the HDT, there was a decrease in the PV CSA supine compared with the pre-HDT PV CSA supine that was similar for all groups (Con: –11%, CM: –21%; tolerant: –10%, intolerant: –16%; P < 0.05). The PV CSA decreased significantly less from supine to standing in the Con than in the CM group (–2 vs. –10% compared with the pre-HDT stand test; P < 0.05). The PV CSA also decreased significantly from supine to standing compared with the pre-HDT stand test in the tolerant group but not in the intolerant group (–20 vs. +2%; P < 0.05). From these findings, we conclude the following. 1) Because the portal vein is the only output from the splanchnic vascular area, we suggest that the lower reduction in the PV CSA and flow associated with orthostatic intolerance was related to a lower splanchnic arterial vasoconstriction. 2) The flywheel exercise CM helped to reduce the distention of the splanchnic network at rest and to maintain partially the splanchnic vasoconstriction, but it did not reduce the orthostatic intolerance.

portal vein; echography; orthostatic tolerance

This article has been cited by other articles:

				D. Fischer, P. Arbeille, J. K. Shoemaker, D. D. O'Leary, and R. L. Hughson Altered hormonal regulation and blood flow distribution with cardiovascular deconditioning after short-duration head down bed rest J Appl Physiol, December 1, 2007; 103(6): 2018 - 2025. [Abstract] [Full Text] [PDF]

				H. Edgell, K. A. Zuj, D. K. Greaves, J. K. Shoemaker, M.-A. Custaud, P. Kerbeci, P. Arbeille, and R. L. Hughson WISE-2005: adrenergic responses of women following 56-days, 6{degrees} head-down bed rest with or without exercise countermeasures Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2007; 293(6): R2343 - R2352. [Abstract] [Full Text] [PDF]

				J. K. Shoemaker, L. Mattar, P. Kerbeci, S. Trotter, P. Arbeille, and R. L. Hughson WISE 2005: stroke volume changes contribute to the pressor response during ischemic handgrip exercise in women J Appl Physiol, July 1, 2007; 103(1): 228 - 233. [Abstract] [Full Text] [PDF]