Influence of interleukin-1 receptor antagonist on [3H]serotonin and histamine release by rat basophilic leukemia-2H3 cells.

Mast cells located in connective tissues are a potent source of vasoactive and inflammatory mediators, such as cytokines. They accumulate in tissues in a wide variety of diseases where their function in most cases in unclear. In this report we provide evidence that rat basophilic leukemia cells (RBLC) cultured with a natural inhibitor of IL-1, interleukin-1 receptor antagonist (IL-1RA) (500 ng/ml) for 48 h, strongly inhibited the spontaneous release of serotonin (5HT) (from 25.2 to 29.9%), and histamine (from 22.50 to 43.49%), compared to untreated cells (control). When IL-IRA-treated and -untreated RBLC were stimulated with a secretagogue (anti-IgE), no difference was found in the percent of 5HT and histamine release. The present studies describe an additional biological activity of IL-1RA, inhibiting histamine and 5HT spontaneous release from RBLC cultures.