TY - JOUR
T1 - Importance of post-exercise hypotension in plasma volume restoration
AU - Hayes, P. M.
AU - Lucas, J. C.
AU - Shi, X.
PY - 2000
Y1 - 2000
N2 - The aim of this study was to test the hypothesis that post-exercise hypotension was the mechanism for the plasma volume and albumin gain during recovery. Seven healthy young men completed two experiments (≥1 week apart) to exercise continuously at 65% of peak aerobic capacity for 60 min followed by the recovery without (experiment 1) or with phenylephrine infusion (experiment 2) to counteract post-exercise hypotension. Heart rate, arterial pressure (Finapres), plasma volume (PV, Evans blue dye dilution), haematocrit, haemoglobin, plasma total solutes (refractometer), albumin, total proteins (colorimetric method), [Na+] and [K+] were not different prior to the experiments. Exercise decreased PV-13.7% (-521 mL) and-14.2% (-566 ml) at the end of 60 min in experiments 1 and 2, respectively, associated with increases in the concentrations of plasma albumin, total protein and solutes. These changes were similar between the two experiments. Following 30 min recovery in experiment 1 the decreased PV was not significantly different from the baseline. Although the volume restoration was complete at the end of 90 min recovery, the change in the albumin concentration was still above zero, indicating a gain of 11 g albumin (P < 0.05). When phenylephrine was infused during recovery, there was no gain in intravascular albumin associated with a sustained decrease in PV (-7% or -280 ml, P < 0.05) observed at the end of experiment 2. These data suggest that post-exercise hypotension may be the mechanism for a gain of intravascular albumin via the lymph return, which enhances plasma water retention and PV restoration during recovery from exercise induced hypovolaemia, even without rehydration.
AB - The aim of this study was to test the hypothesis that post-exercise hypotension was the mechanism for the plasma volume and albumin gain during recovery. Seven healthy young men completed two experiments (≥1 week apart) to exercise continuously at 65% of peak aerobic capacity for 60 min followed by the recovery without (experiment 1) or with phenylephrine infusion (experiment 2) to counteract post-exercise hypotension. Heart rate, arterial pressure (Finapres), plasma volume (PV, Evans blue dye dilution), haematocrit, haemoglobin, plasma total solutes (refractometer), albumin, total proteins (colorimetric method), [Na+] and [K+] were not different prior to the experiments. Exercise decreased PV-13.7% (-521 mL) and-14.2% (-566 ml) at the end of 60 min in experiments 1 and 2, respectively, associated with increases in the concentrations of plasma albumin, total protein and solutes. These changes were similar between the two experiments. Following 30 min recovery in experiment 1 the decreased PV was not significantly different from the baseline. Although the volume restoration was complete at the end of 90 min recovery, the change in the albumin concentration was still above zero, indicating a gain of 11 g albumin (P < 0.05). When phenylephrine was infused during recovery, there was no gain in intravascular albumin associated with a sustained decrease in PV (-7% or -280 ml, P < 0.05) observed at the end of experiment 2. These data suggest that post-exercise hypotension may be the mechanism for a gain of intravascular albumin via the lymph return, which enhances plasma water retention and PV restoration during recovery from exercise induced hypovolaemia, even without rehydration.
KW - Albumin
KW - Exercise dehydration
KW - Lymph return
KW - Phenylephrine
KW - Post-exercise hypotension
UR - http://www.scopus.com/inward/record.url?scp=0034201670&partnerID=8YFLogxK
U2 - 10.1046/j.1365-201x.2000.00728.x
DO - 10.1046/j.1365-201x.2000.00728.x
M3 - Article
C2 - 10848641
AN - SCOPUS:0034201670
VL - 169
SP - 115
EP - 124
JO - Acta Physiologica Scandinavica
JF - Acta Physiologica Scandinavica
SN - 0001-6772
IS - 2
ER -