Body Fluid Changes, Cardiovascular Deconditioning and Metabolic Impairment Are Reversed 24 Hours after a 5-Day Dry Immersion  

作　　者：Mickael Coupe Elena Tomilovskaya Francoise Larcher Bertrand Diquet Liudmila KhPastushkova Inesa BKozlovskaya Irina MLarina Guillemette Gauquelin-Koch Vladimir AKulchitsky Marc-Antoine Custaud Nastassia MNavasiolava 

机构地区：[1]CNRS UMR 6214,INSERM U1083,Angers University,Angers,France [2]Associated French-Russian Laboratory CaDyWEC,Angers,France&Moscow,Russia [3]Institute of Biomedical Problems RAS SSC,Moscow,Russia [4]Biochemistry Laboratory,Angers University Hospital,Angers,France [5]Pharmacokinetics Laboratory,Angers University Hospital,Angers,France [6]French Space Agency(CNES),Paris,France [7]Institute of Physiology,National Academy of Sciences,Minsk,Belarus

出　　处：《Open Journal of Nephrology》2013年第1期13-24,共12页肾脏病（英文）

摘　　要：Dry immersion is an effective and useful model for research in physiology and physiopathology. The focus of this study was to provide integrative insight into renal, endocrine, circulatory, autonomic and metabolic effects of dry immersion. We assessed if the principal changes were restored within 24 h of recovery, and determined which changes were mainly associated with immersion-induced orthostatic intolerance. Five-day dry immersion without countermeasures, and with ad libitum water intake, standardized diet and a permitted short daily rise was performed in a relatively large sample for this experiment type (14 healthy young men). Reduction of total body water derived mostly from extracellular compartment, and stabilized rapidly at the new operating point. Decrease in plasma volume was estimated at 20% - 25%. Five-day immersion was sufficient to impair metabolism with a decrease in glucose tolerance and hypercholesterolemia, but was not associated with pronounced autonomic changes. Five-day immersion induced marked cardiovascular impairment. Immediately after immersion, over half of the subjects were unable to accomplish the 20-min 70° tilt;during tilt, heart rate and total peripheral resistance were increased, and stroke volume was decreased. However, 24 hours of normal physical activity appeared sufficient to reverse orthostatic tolerance and all signs of cardiovascular impairment, and to restitute plasma volume and extracellular fluid volume. Similarly, metabolic impairment was restored. In our study, the major factor responsible for orthostatic intolerance appeared to be hypovolemia. The absence of pronounced autonomic dysfunction might be explained by relatively short duration of dry immersion and daily short-time orthostatic stimulation.Dry immersion is an effective and useful model for research in physiology and physiopathology. The focus of this study was to provide integrative insight into renal, endocrine, circulatory, autonomic and metabolic effects of dry immersion. We assessed if the principal changes were restored within 24 h of recovery, and determined which changes were mainly associated with immersion-induced orthostatic intolerance. Five-day dry immersion without countermeasures, and with ad libitum water intake, standardized diet and a permitted short daily rise was performed in a relatively large sample for this experiment type (14 healthy young men). Reduction of total body water derived mostly from extracellular compartment, and stabilized rapidly at the new operating point. Decrease in plasma volume was estimated at 20% - 25%. Five-day immersion was sufficient to impair metabolism with a decrease in glucose tolerance and hypercholesterolemia, but was not associated with pronounced autonomic changes. Five-day immersion induced marked cardiovascular impairment. Immediately after immersion, over half of the subjects were unable to accomplish the 20-min 70° tilt;during tilt, heart rate and total peripheral resistance were increased, and stroke volume was decreased. However, 24 hours of normal physical activity appeared sufficient to reverse orthostatic tolerance and all signs of cardiovascular impairment, and to restitute plasma volume and extracellular fluid volume. Similarly, metabolic impairment was restored. In our study, the major factor responsible for orthostatic intolerance appeared to be hypovolemia. The absence of pronounced autonomic dysfunction might be explained by relatively short duration of dry immersion and daily short-time orthostatic stimulation.

关 键 词：Physical Inactivity Modeled Weightlessness Water-Electrolyte Balance Body Fluid Compartments Orthostatic Intolerance 

分 类 号：R73[医药卫生—肿瘤]