Concanavalin A-induced histamine release from normal rat mast cells

Area of Science:

• Immunology
• Cell Biology
• Pharmacology

Background:

• Mast cells are key players in allergic reactions, releasing histamine.
• Concanavalin A (con A) is a lectin known to interact with cell surface glycoproteins.

Purpose of the Study:

• To investigate the mechanism of histamine release from rat mast cells induced by Concanavalin A (con A).
• To explore the role of phosphatidylserine (PS) in modulating con A-induced histamine release.
• To identify methods for controlling and terminating the histamine release process.

Main Methods:

• Utilized normal rat mast cells.
• Measured histamine release in response to varying concentrations of con A and phosphatidylserine (PS).
• Conducted binding studies to assess con A-mast cell interactions.
• Employed alpha-methyl-D-mannose to inhibit con A binding and histamine release.

Main Results:

• Con A induced dose- and temperature-dependent, noncytotoxic histamine release only in the presence of PS.
• Optimal histamine release (27.3%) occurred at 100 mug/ml con A.
• Histamine release initiated within 30 seconds and completed within 45 minutes.
• PS alone did not induce histamine release; its effect was concentration-dependent.
• Mast cells bound significant amounts of con A without releasing histamine.
• Alpha-methyl-D-mannose inhibited con A binding and rapidly terminated histamine release.

Conclusions:

• Con A-induced histamine release from mast cells requires the presence of phosphatidylserine (PS).
• The binding of con A to mast cells can be dissociated from histamine release.
• The con A-PS system provides a controllable model for studying histamine release.
• Alpha-methyl-D-mannose serves as an effective agent to rapidly stop the histamine release reaction.