Flow behavior of ATP-depleted human erythrocytes 1

Abstract

Earlier reports of increased blood viscosity and greatly increased RBC membrane rigidity consequent to adenosine triphosphate (ATP) depletion have been followed by studies demonstrating minimal or nonexistent alterations in the mechanical properties of depleted RBC membranes. The present study was undertaken to provide additional information on the rheological behavior of ATP-depleted human erythrocytes and to examine the influence of RBC morphology on the flow behavior of these cell suspensions. ATP depletion via 24 hr incubation at 37°C caused: (1) RBC crenation (discocyte-echinocyte): (2) increased low shear rate viscosity; (3) enhanced non-Newtonian flow behavior. Virtually identical flow data were obtained with fresh ATP-rich RBC which were crenated via 2,4-dinitrophenol (DNP); shape change and viscometric behavior were dose related. Both ATP-depleted and fresh DNP-treated cells could be returned to near-normal morphology and to normal flow behavior with the addition of the stomatocytic agent chlorpromazine hydrochloride. These morphology-rheology results thus offer an alternative interpretation of the earlier viscometric data and suggest that decreased in vivo cell survival and disturbed microcirculatory flow associated with ATP-poor RBC may be related to altered cellular morphology.