Distribution of spermidine and spermine in blood from cystic fibrosis patients and control subjects

Abstract

Previous studies have shown an abnormality of the spermidine to spermine (Spd/Spm) ratio in whole blood of cystic fibrosis homo and heterozygotes. To investigate Spd and Spm distribution among blood components as a possible cause of the abnormality, blood was fractionated using Rabinowitz's glass bead technique and Boyum's Ficoll Hypaque method. Free (unconjugated) polyamines were extracted with perchloric acid and quantitated on an amino acid analyzer. In controls, mean ± SEM concentrations in nmoles/109 cells of Spd and Spm, respectively, were 1.02±0.08 and 0.894±0.28 for erythrocytes; 126±31 and 357±105 for lymphocytes; 36±16 and 240±33 for granulocytes; and <0.5 and <0.5 nmoles/ml for plasma. When converted to the concentration in whole blood, it was found that greater than 90% of Spd and over 70% of Spm was associated with erythrocytes. While the higher cellular concentration in leukocytes was not unexpected, the fact that Spd and Spm in whole blood were primarily associated with erythrocytes was a new finding. Comparison with controls revealed that the Spd/Spm ratio in both whole blood and erythrocytes was significantly higher in the group of cystic fibrosis patients.