IgE receptors from rat intestinal mucosal and peritoneal mast cells show mast cell subtype-specific differences

High- (alpha chain) and low-affinity IgE receptors from purified populations of rat intestinal mucosal (IMMC) and peritoneal mast cells (PMC) were characterized by SDS-PAGE. Receptor expression and molecular weight were compared. IMMC yielded 59-kilodalton (kDa) alpha chains of the high-affinity receptors and two forms (58, 50 kDa) of low-affinity receptors, whereas PMC possessed only 51-kDa alpha chains and 56-kDa low-affinity receptors. These differences extend the evidence for functional diversity between mast cell subtypes.