FACTORS DETERMINING SPONTANEOUS HISTAMINE-RELEASE FROM HUMAN BASOPHILS PURIFIED WITH PERCOLL GRADIENTS AND DYNABEADS

Identification of factors influencing histamine release from purified and cultured basophil leukocytes is important for proper interpretatio n of results obtained on histamine release. This paper describes facto rs that influence spontaneous histamine secretion from human basophil leukocytes purified on Percoll gradients, followed by negative selecti on with Dynabeads. Anti-IgE and recombinant human interleukin-3 were u sed as model stimulants, and the purified basophil leukocytes were sti mulated for 10 min and 6 h. The effect of the following conditions was examined: Percoll temperature, cell-suspension density, and serum in the media. The results showed that low Percoll temperature, high cell- suspension density, and the presence of serum in the media decreased s pontaneous histamine release and increased maximal net histamine relea se upon stimulation.