COMPARISON OF HISTAMINE-RELEASE FROM HUMAN BLOOD MONOCYTES, LYMPHOCYTES, ADENOIDAL AND SKIN MAST-CELLS

Monocytes and lymphocytes from human blood contain 0.043 +/- 0.007 and 0.053 Histamine Release +/- 0.014 pg histamine/cell, respectively, wh ich can be released by a number of stimulants (A 23187, C5a, substance P, specific allergen). The release process takes 60-120 min to reach its end point, in contrast to tissue mast cells which complete the rel ease within 1-3 min. Both, ketotifen (10(-7)-10(-5) M) and disodium cr omoglycate (10(-5)-10(-3) M) inhibited histamine release dose dependen tly up to 40-45%, which might be particularly relevant during the late r stages of acute allergic or pseudoallergic reactions.