Rat peritoneal mast cells release dipeptidyl peptidase II

Area of Science:

• Biochemistry
• Cell Biology
• Immunology

Background:

• Mast cells are key players in allergic responses and inflammation.
• Dipeptidyl peptidase II (DPP II) is an enzyme with largely unknown functions in immune cells.
• Understanding enzyme activity in specific cell types is crucial for elucidating biological processes.

Purpose of the Study:

• To investigate the activity and release of dipeptidyl peptidase II (DPP II) in rat mast cells.
• To compare DPP II activity between mast cells and macrophages.
• To explore the regulation and potential function of mast cell DPP II.

Main Methods:

• Purification of rat peritoneal mast cells and macrophages.
• Enzymatic assays to measure DPP II activity.
• Stimulation of cells with Compound 48/80, Substance P, and antigen/IgE.
• Analysis of DPP II release.

Main Results:

• Purified rat mast cells showed 10-20 times higher DPP II activity than macrophages.
• DPP II was dose-dependently released from mast cells and peritoneal-lavage cells upon stimulation.
• Histamine and Zn2+ significantly inhibited DPP II activity.
• No significant release of DPP II was observed from purified macrophages.

Conclusions:

• Rat mast cells possess significantly higher DPP II activity compared to macrophages.
• Mast cell activation leads to the release of DPP II, indicating its involvement in cellular responses.
• Inhibitory effects of histamine and Zn2+ suggest granule-associated regulation of DPP II.
• Mast cell-derived DPP II may play a role in connective tissue remodeling.