Effect of dichloromethane on sickle cells. An in vitro water proton magnetic resonance relaxation study

To examine the manner in which dichloromethane inhibits sickling, sickle blood was subjected to both prevention and reversal schemes over a range of CH₂Cl₂ vapor pressures. Following CH₂Cl₂-treatment, the rotating frame spin lattice relaxation time (T_1?) of water protons in deoxygenated packed sickle cells was measured, cell types in a deoxygenated fixed sample were counted, and the extent of hemolysis determined. At CH₂Cl₂ vapor pressures above 200 mm, the NMR relaxation rate decreased sharply, the extent of hemolysis increased, the fraction of sickled cells and other abnormal erythrocytes decreased, and the fraction of biconcave discs increased. Apparently CH₂Cl₂ is absorbed by the cell membrane and preferentially lyses sickled cells and other abnormal cells. Part of the decrease in NMR relaxation rate with increased CH₂Cl₂ pressure is due to a larger fraction of discs, but an additional factor probably arises from CH₂Cl₂ inhibition of hemoglobin S gelation.