[Enzyme immunoassay for the determination of serotonin in stored platelet concentrates].

A new enzyme immunoassay (EIA) was applied on measurements of serotonin (5-HT) in stored platelet concentrates (PC). PC were prepared by apheresis of two separators (Cobe, Fresenius) or from buffy coats and stored for a period of 7 days at 22 degrees C and agitating. Measurements were done in pellets and suspension medium (plasma).

Active uptake of serotonin as viability parameter of stored platelets.

The platelet-plasma serotonin (5-HT) exchange in different apheresis products and platelet concentrates (PCs) from buffy coats was studied for quality control over a period of 7 days. In PCs with steadily decreasing pH due to inappropriate gas exchange the platelet 5-HT concentration increases significantly (> 10% positive netto uptake) during the 1st day of storage. Thereafter platelet serotonin drops rapidly with t1/2 = 1 day at pH < 6.

[Oxygen affinity and regeneration capacity of SAG-M and PAGGS-M stored erythrocytes].

In order to estimate the leftward shift of the oxygen dissociation curve of hemoglobin following storage of red blood cells (rbc) in the additive solutions SAG-M and PAGGS-M, respectively, we performed blood gas analyses after equilibrating the cells with a gas mixture containing 4% of O2 and 5% of CO2 at pH 7.4 and 37 degrees C. Additionally, we took advantage of these nearly physiological conditions to measure the recovery of the hemoglobin function in vitro.

[Comparison of erythrocyte concentrations of ATP, ADP, AMP and 2,3-BPG in storage of five different additive solutions and in serum].

In this study, we compared the ability of serum and of 5 additive solutions for the liquid storage of red blood cells to preserve the cellular contents of 2,3-BPG and the adenylate nucleotides ATP, ADP and AMP. As to the adenylates, PAGGS-M showed the best results. However, the difference to SAG-M was significant only after 7 weeks.