Permeability of human granulocytes to water: rectification of osmotic flow

The permeability of human granulocytes to water was studied for samples of that population with an electronic particle counter. Changes in volume were monitored as these samples were introduced suddenly into hypo- and hypertonic osmotica. Temperature and concentration sensitivity analyses of the permeability coefficients were carried out. An apparent rectification of water flow seems to occur with the water permeability being three times higher for endosmotic flow than for exosmotic flow. The estimated water permeability at the reference temperature 20 degrees C was for exosmotic flow 2.04 +/- 0.02 x 10(-12) kgmol N-1 s-1 with an apparent transfer energy of 4.76 +/- 0.09 x 10(7) J kgmol-1, and for endosmotic flow 6.05 +/- 0.07 x 10(-12) kgmol N-1 s-1 with an apparent transfer energy of 4.9 +/- 0.1 x 10(7) J kgmol-1.