Search

Production by normal human erythrocytes of a substrate for cholinesterase has been demonstrated. At body temperature, the formation and hydrolysis of the cholinesterase substrate is delicately controlled. At lowered temperatures, 0 to -1.5 C., production of cholinesterase substrate greatly exceeds its hydrolysis. The quantity of cholinesterase substrate capable of exerting its influence governs the quantity of dextrose converted to lactic acid by the erythrocyte under anaerobic conditions. The observations corroborate and extend the suggestion of Lindvig, Greig, and Peterson that cholinesterase is part of a cellular system governing erythrocyte permeability. The balance between production and hydrolysis of cholinesterase substrate at low temperature exhibits the same undulating fluctuations during red cell storage that have been noted for other erythrocyte metabolic functions.

The fluctuating capacity of stored erythrocytes to release gas when suspended in the presence of dextrose in Krebs-Ringer bicarbonate solution in an atmosphere of 5 per cent CO2-95 per cent N2 is demonstrated. A not dissimilar fluctuation of the cholinesterase activity of the stored cells is reported. Possible seasonal variation in the state of red cells is suggested. Some implications of these observations for erythrocyte storage are suggested.

It is possible to prepare self-stabilizing solutions of hemoglobin from human erythrocytes by the use of dextrose, nicotinic acid amide and ammonia during the preparation and in the final solutions themselves. Co++, Mn++ and Mg++ ions, nile blue and hexose diphosphate contribute to the speed of stabilization of these solutions. Stabilization is obtained by the faculty of the solutions, presumably by enzymic action, to convert the hemoglobin to the reduced form and to maintain it in this form. The hemoglobin solutions described are suitable for intravenous administration.