Open AccessRegional blood flow in microgravity: adaptation and deconditioning
Author(s) -
Philippe Arbeille,
F Achaïbou,
G Fomina,
Pottier Jm,
M. Porcher
Publication year - 1996
Publication title -
medicine and science in sports and exercise
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.703
H-Index - 224
eISSN - 1530-0315
pISSN - 0195-9131
DOI - 10.1097/00005768-199610000-00037
Subject(s) - orthostatic intolerance , medicine , deconditioning , peripheral , cardiology , orthostatic vital signs , vascular resistance , spaceflight , bed rest , presyncope , cerebral blood flow , hemodynamics , heart rate , blood pressure , engineering , aerospace engineering
The objectives were to evaluate cardiac and peripheral changes induced by microgravity with and without countermeasures (CM), to assess the peripheral response to orthostatic tests (tilt, LBNP). Inflight or HDT, we used echography and Doppler to assess the left heart function and the peripheral arteries. We studied the cardiovascular system during 1) 21-d and 25-d spaceflights without CM, 2) 14.d spaceflight with "bracelets" CM, 3) 28-d HDT with and without LBNP, and 4) 30-d HDT with and without Exercise+LBNP. Similar peripheral circulation changes were noticed in both astronauts and HDT subjects without CM. There was a decrease in renal, cerebral, and femoral vascular resistances and maintenance of cerebral flow at rest, and a lack of increase in lower limb vascular resistance and abnormal flow redistribution during orthostatic tests. Conversely, with CM at rest, cerebral and renal vascular resistances stayed elevated and femoral resistance decreased, but less than without countermeasures. Lower limb vascular resistance increased normally, peripheral flows were adequately redistributed during orthostatic tests, and no orthostatic intolerance was observed. This confirms the efficiency of countermeasures (LBNP, exercise, cuffs) in preserving the vasomotor tone in most peripheral areas at rest and reducing the development of orthostatic intolerance.