Abstract
Polyamine levels in blood cells were suggested as a sensitive and specific indicator for cancer. We report here a simple and sensitive method to determine free polyamine levels in blood cells. Using 0.2ml of hemolyzed blood, free polyamines in blood were measured by a putrescine oxidase chemiluminescent method. The analytical specificity and sensitivity of this method were good enough for clinical use.
The coefficient of variation (CV) of within-run (n=9) was 2.1% for a blood sample with 20.4μmol/L of free polyamine, and the CV of between-run (n=12) was 4.0% for a sample with 20.3μmol/L of polyamine. Analytical recovery was about 100% for all free polyamines except spermine. The linearity of measurement by this method was observed in the range of spermidine from 0 to 70μmol/L. The results determined by this method were correlated well with those determined by an HPLC method (r=0.967). Since the concentrations of free polyamine in plasma are negligibly low as compared to those in blood cells, the free polyamine concentrations in blood as measured by this method can represent the free polyamine concentrations in blood cells. The free polyamine levels in blood cells (PBC), when devided by the corresponding hematocrit values,were 41.0±10.3uM/Ht for healthy subjects (12 males and 27 females). High PBC were observed in some patients with cancer. The usefulness of PBC for screening cancer, however, remaines to be established.
