The Effects of Nucleosides On the Resistance of Normal Human Erythrocytes to Osmotic lysis12

Abstract

Incubation of freshly-obtained, washed, human erythrocytes with adenosine, guanosine, inosine, 2,6-diaminopurine riboside or xanthosine in isotonic pH 7.3 to 7.4 sodium phosphate buffer for 2 hours at 37t resulted in marked enhancement of resistance to osmotic lysis on exposure to hypotonic solutions of phosphate buffer. This effect was also observed, but to a much lesser extent, with glucose or ribose-5-phosphate. This enhanced osmotic resistance was associated with a considerable uptake and metabolism of the ribose moiety of the purine ribosides, and a major portion of the metabolized ribose could be accounted for by increased lactate production. Incubation with a number of other compounds (nucleotides, pyrimidine ribosides, purine and pyrimidine deoxyribosides, benzimida-zole riboside, adenine glucoside, purine riboside, phosphorylated sugars, some compounds of the tricarboxylic acid cycle and several amino acids) did not result in enhanced osmotic resistance. It is suggested that the metabolism of purine ribosides in vitro provides energy which may be utilized in maintenance of the structural integrity of the erythrocyte subjected to osmotic stress.