ORIGINAL ARTICLES   

Gazzetta Medica Italiana Archivio per le Scienze Mediche 2002 February;161(1):7-18

Copyright © 2002 EDIZIONI MINERVA MEDICA

language: English

Intercompartmental, plasma and urinary biochemical changes in healthy subjects during acute and rigorous bed rest and ambulation

Zorbas Y. G. ¹, Yarullin V. L. ¹, Denogratov S. D. ², Kuznetsov N. A. ²

¹ Higher Institute of Biochemistry, Gomel, Belarus; ² Hypokinetic Physiology Laboratory, Athens, Greece

Back­ground. ­Body hydra­tion homeo­stasis under­goes sig­nif­i­cant ­changes ­during a rig­orous bed ­rest (RBR), how­ever, ­little is ­known ­about the ­effect of ­acute bed ­rest (ABR) (­abrupt con­fine­ment to RBR) on ­body hydra­tion. We ­aimed to estab­lish ­body hydra­tion homeo­stasis ­during ABR and RBR.
­Methods. ­Studies ­were ­done ­during ­prebed ­rest (BR) ­period of 3 ­days and ­during 7 ­days ­period of ABR and RBR. ­Thirty ­healthy ­male indi­vid­uals ­aged, 24.6±5.7 ­years ­were ­chosen as sub­jects. ­They ­were ­divided ­into 3 ­groups: unre­stricted ambu­la­tory con­trol sub­jects (­UACS), ­acute bed ­rested sub­jects (­ABRS) and rig­orous bed ­rested sub­jects (­RBRS). ­Acute bed ­rested sub­jects con­fined ­abruptly to RBR, ­while ­they did not ­have any ­prior knowl­edge of the ­exact ­date and ­time ­when ­they ­would be ­asked to ­stay in bed. Rig­orous bed ­rested sub­jects sub­mitted to RBR on a pre­de­ter­mined ­date and ­time ­known to ­them ­right ­from the ­start of the ­study.
­Results. ­Fluid ­loss, uri­nary and ­plasma ­sodium (Na) and potas­sium (K), uri­nary and ­plasma osmo­lality, ­whole ­blood hem­a­tocrit (Hct) and hemo­globin (Hb), and ­total ­plasma pro­tein ­level ­increased sig­nif­i­cantly (p≤0.05), ­while extra­cel­lular ­volume (ECV), ­plasma ­volume (PV), red ­cell ­volume (RCV), ­blood ­volume (BV) and inter­sti­tial ­volume (IV) and ­fluid ­intake ­decreased sig­nif­i­cantly (p≤0.05) in ­ABRS and ­RBRS ­when com­pared ­with ­their pre-BR ­values and the ­values in ­UACS. How­ever, the meas­ured param­e­ters ­changed sig­nif­i­cantly (p≤0.05) ­more in ­ABRS ­than ­RBRS. ­Fluid ­loss, ­fluid ­intake, uri­nary and ­plasma Na and K, Hct, Hb, ­plasma pro­tein, uri­nary and ­plasma osmo­lality, ECV, PV, RCV, BV and IV ­change insig­nif­i­cantly (>0.05) in ­UACS ­when com­pared ­with ­their pre-BR ­values.
Con­clu­sions. It was con­cluded, ­that the ­more ­abruptly mus­cular ­activity is ­restricted the ­greater dehy­dra­tion of the ­body ­there is, and prob­ably in indi­vid­uals ­whose mus­cular ­activity is ­abruptly ter­mi­nated.