It is inferred from analysis of normal physiology data that erythrocyt
e membrane permeability for the oxygen in human organism must decrease
at least 1000 times after oxygenation in the lungs. And the cell memb
ranes of other tissues are also capable to change their permeability f
or the oxygen. The kinetics of blood oxygenation and deoxygenation is
investigated in order to check this conclusion. Measurements of blood
oxygenation kinetics together with oxygen tension in blood plasma allo
ws to determine average value of membrane permeability decrease being
equal 70 times. Biological expediency of fluctuation of the erythrocyt
e membrane permeability is discussed. A method of determination of opt
ical oxymeters calibration and hemoglobin-oxygen equilibrium curve for
the blood is proposed. It does not require the oxygen equilibrium bet
ween the blood plasma and the erythrocyte cytoplasm and uses only read
ings of a calibrated oxymeter. Variation of non-equilibrial state of t
he erythrocyte during the oxygen saturation is considered as the cause
of the membrane permeability fluctuation. Erythrocyte parameters, suc
h as its volume, substances concentration, transmembrane potential, ar
e shown to depend on the amount of the substances not penetrating thro
ugh the membrane and on osmotic pressure. A hypothesis of the transmem
brane potential influence on the membrane permeability is proposed. Th
e external electric field is shown experimentally to accelerate the bl
ood deoxygenation.