Human C5a induces a substantial histamine release in human basophils but not in tissue mast cells.
The histamine-releasing effect of human C5a was compared with that of concanavalin A in blood basophils and isolated adenoidal mast cells from the same donors. In basophils, C5a (10 ng/ml) induced a significant histamine release (7.5 +/- 2.1%, corrected value). In isolated adenoidal mast cells C5a had only a marginal effect (2% histamine release), although the cells responded markedly to concanavalin A stimulation (about 13% release). The results support the view that the heterogeneity of mast cells and basophils is also reflected in the expression of anaphylatoxin receptors on their surface.
D000234:Adenoids / Q000166:cytology; D001491:Basophils / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D003182:Complement C5 / Q000494:pharmacology*; D015936:Complement C5a; D003208:Concanavalin A / Q000494:pharmacology; D006636:Histamine Release; D006801:Humans; D008407:Mast Cells / Q000378:metabolism*; D011863:Radioimmunoassay
D003182:Complement C5; D003208:Concanavalin A; D015936:Complement C5a