Some in Vitro Effects of Adenine Added to Stored Blood

When adenine was added to freshly collected ACD blood and the blood incubated at 37 C. for one or two days, the concentration of ATP and adenine nucleotides (AMP + ADP + ATP) was higher than in the same blood without adenine. The addition of inosine with adenine was even more effective. Adenine was used by the red cells and the effective amounts of adenine to be added varied with the experimental conditions, for example, length of incubation. When adenine or adenine and inosine were incubated with outdated ACD blood, the ATP and adenine nucleotide concentrations rose, indicating that synthetic abilities were still present in red cells which had deteriorated energetically as a result of storage in citrate in the cold. When outdated red cells were returned to a more normal p H, the ATP levels increased. When adenine addition was included along with neutralization, the effects were remarkable, the ATP and adenine nucleotide levels going even above normal fresh blood levels. These experiments suggest that added adenine enhances ATP synthesis and allows formulation of a scheme for the participation of adenine in the metabolic reactions of stored cells.