Plasma Serotonin Levels in Stored Human Blood

Abstract

Plasma serotonin levels were determined in stored human blood over a 21-day period in 3 groups of experiments by a reproducible method utilizing a chemical extraction and a spectrophotofluorometric analysis. There were wide variations in plasma serotonin levels in plasma samples obtained at random times from blood containers in the Kings County Hospital Center Blood Bank during a 21-day storage period. When plasma serotonin levels were determined in aliquots obtained from 1 pooled blood sample on specific days during the 21-day storage period, serotonin levels were increased from 0.011 to 0.030 [mu]g/ml on day 1 to 0.025 to 0.155 [mu]g/ml on day 21. There was little difference in plasma serotonin levels of samples containing plasma in contact with the cellular elements of blood and of samples containing plasma not in contact with the cellular elements of blood from day 1 through day 9 of storage. After day 9 plasma serotonin levels rose in those samples containing cellular elements of blood, and the rise was proportional to the concentration of the cellular elements of the sample; plasma serotonin levels did not rise in those samples which contained only plasma.