Abstract
We evaluated cytotoxic factor released from rat basophilic leukemia cells (RBL) sensitized with anti-ovalbumin (OVA) mouse serum after incubation with OVA. The cytotoxic activity of this factor was completely blocked by anti-mouse tumor necrosis factor-α (mTNF-α) specific antibody. Therefore, we concluded that by triggering the IgE receptor, RBL could produce and release TNF-α.