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R B Dawson

Publications and source records attributed to R B Dawson.

At least 37 records · Page 2Linked to original sources

Preservation of erythrocytes using metabolic regulators and mutrients. V. Inosine and methylene blue.

Methylene blue and inosine have been shown to stimulate glycolytic metabolism in the erythrocytes, increasing the concentration of 2.3-diphosphoglycerate (2,3-DPG), which is necessary for hemoglobin function, by regulating oxidative metabolism and providing a five-carbon nutrient for glycolysis, respectively. However, a recent study suggested that the methylene blue effect was dependent on the presence of inosine. This study was designed to establish, if possible, the existence of a methylene blue effect and to confirm the usefulness of inosine. The optimal concentration of inosine for increasing 2,3-DPG synthesis in a CPD-adenine preservative is confirmed to be 10--15 mM. Concentrations of 2,3-DPG were maintained in the erythrocytes at normal or higher levels for 21 days of storage with 10 or 15 mM inosine, whether the methylene blue was present or not. However, when methylene blue was present, 2,3-DPG concentrations were significantly better maintained.

Adenine↗

Hemoglobin function in stored blood, XVII. Maintenance of red cell 2,3 DPG (function) and ATP (viability) for six weeks in ACD or CPD-adenine-inosine-methylene blue.

Blood preservatives containing adenine for six week storage have been prepared with inosine and methylene blue at various pH levels in order to maintain, 23-DPG levels for immediate oxygen transport upon transfusion. In one experiment, the adverse effect of a high pH on ATP maintenance was demonstrated in the presence of methylene blue and inosine. In this and other experiments it was clear that ATP was better maintained in low pH preservatives and DPG better maintained in higher pH preservatives. However, 2,3-DPG levels were kept from falling with CPD-adenine-inosine over a wide range of pH values. A CPD-adenine-inosine preservative at a pH 5.8 maintained normal DPG levels for three weeks of storage. A similar preservative but with a pH of 6.6 maintained normal DPG levels for 35 days of storage. It is suggested that if all blood bank units are going to have normal DPG levels for optimal oxygen transport at the time of transfusion then a CPD preservative with a higher pH and/or metabolic nutrients and regulators such as inosine or methylene blue would be required.

Adenine↗

Hemoglobin function in stored blood. XIII. A citrate-adenine preservative with optimal pH to maintain red cell 2,3-DPG (function) and ATP (viability).

Increasing pH by a 0.5 increment over the commonly used preservative, acid-citrate-dextrose with adenine (ACD-Ad), results in a significant improvement in 2,3-DPG, with no significant loss in concentrations of ATP. The intermediate pH preservative, 6.0, also had ATP concentrations which equaled those of the low pH preservatives, 5.0 and 5.5, from the 21st to the 42nd day of storage. A citrate-adenine preservative, with a pH between 5.5 and 6.0, would seem to be optimal for maintenance of hemoglobin function and red cell viability, as determined by measurements of 2,3-DPG and ATP concentrations.

Adenosine Triphosphate↗