Sodium-cromoglycate (Cromolyn) selectively increases the binding and phagocytosis of unsensitized target cells by rat peritoneal macrophages.

The influence of sodium-cromoglycate (cromolyn) on the binding and ingestion of sheep erythrocytes (SRBC) by elicited rat peritoneal macrophages (M phi) was studied using unsensitized SRBC. SRBC sensitized by homologous IgG or by IgM and complement as target cells. Preincubation of M phi with the drug (1 nM/1-2 mM/1) markedly enhanced both binding and ingestion of uncoated SRBC. The IgG-related increment in binding and phagocytosis was not significantly influenced by the drug. When target cells were coated by IgM and complement cromolyn pretreatment was ineffective. Preincubation of M phi by bovine brain gangliosides (BBG) diminished the cromolyn-induced enhancement of target cell binding and phagocytosis. When SRBC were pretreated by BBG, an increase of binding and phagocytosis was observed. These data suggest that cromoglycate may enhance the capacity of M phi to bind erythrocytes via ganglioside structures. Coating SRBC by complement components appears to interfere with binding of erythrocytes to M phi ganglioside receptors.