Red cell hemoglobin, hydrogen ion and electrolyte concentrations during exercise in trained and untrained subjects.
Red cell concentrations of hemoglobin (MCHC), H+, Na+, K+, Mg++, cl- were measured in femoral venous blood of six untrained (UT), six endurance trained (TR) and three semitrained (ST) subjects during graded increasing work (4, 8, 12, 18 and 24 mkp/s, 10-15 min on each step) on a bicycle ergometer. Before exercise no significant differences were detected for the measured variables when comparing UT and TR. During exercise MCHC, [Na+], [K+] and [Mg++] remained constant indicating lack of water shift into the erythrocytes in spite of a marked acidosis (lowest pH Blood value 7.225). This lack resulted from an elevated extracellular osmolality. [H+]Ery and [Cl-]Ery maximally increased by 2.0 X 10(-8) eq/kg H2O and 10 meq/l, respectively. The change was markedly greater in UT than in TR at equal load. However, if [H+] Ery and [Cl-] Ery were related to pH of whole blood, differences between groups, almost disappeared and the ions were distributed as predictable from in vitro experiments (Fitzsimmons and Sendroy, 1961). Behaviour of H+ and Cl- may be of importance for oxygen dissociation under in vivo conditions.
D000328:Adult; D002712:Chlorides / Q000097:blood; D004573:Electrolytes / Q000097:blood*; D004912:Erythrocytes / Q000032:analysis*; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000097:blood; D008297:Male; D005082:Physical Exertion; D010809:Physical Fitness; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood
D002712:Chlorides; D004573:Electrolytes; D006454:Hemoglobins; D012964:Sodium; D008274:Magnesium; D011188:Potassium