Histamine release from rat mast cells sensitized with mouse antiserum

Area of Science:

• Immunology
• Pharmacology

Background:

• Mast cells play a crucial role in allergic reactions through histamine release.
• Antigen-induced histamine release is a well-studied phenomenon, but non-antigen-induced pathways are less understood.

Purpose of the Study:

• To investigate the mechanisms of antigen-induced and non-antigen-induced histamine release from rat mast cells.
• To evaluate the effects of specific antiallergic drugs on these histamine release pathways.

Main Methods:

• Sensitization of rat peritoneal mast cells in vitro with mouse anti-ovalbumin serum.
• Induction of histamine release using antigen (ovalbumin) and non-antigenic stimuli.
• Treatment of mast cells with antiallergic drugs including quercetin, verapamil, theophylline, and disodium cromoglycate.

Main Results:

• Heat-labile factors in mouse antiserum and normal mouse serum contributed to non-antigen-induced histamine release.
• Phosphatidyl serine and calcium ions (Ca++) induced histamine release in the absence of antigen when mast cells were treated with these factors.
• Quercetin and verapamil were found to primarily block calcium-gate opening during antigen-antibody interactions.
• Theophylline and disodium cromoglycate were observed to inhibit calcium passage through open calcium channels.

Conclusions:

• Non-antigen-induced histamine release involves heat-labile factors and can be modulated by phosphatidyl serine and calcium.
• Antiallergic drugs exhibit distinct mechanisms of action, targeting different stages of calcium influx during mast cell degranulation.
• These findings provide a deeper understanding of mast cell activation and offer potential therapeutic strategies for allergic diseases.