Related Experiment Videos
A patch-clamp study: secretagogue-induced currents in rat peritoneal mast cells.
The American Journal of Physiology
|March 1, 1989
Summary
This study provides electrophysiological evidence for calcium (Ca2+) channels in rat mast cells, crucial for stimulus-secretion coupling. The findings identify specific ion channel properties involved in calcium influx during cellular responses.
Area of Science:
- Immunology
- Cell Biology
- Biophysics
Background:
- Plasma membrane Ca2+ entry is vital for mast cell stimulus-secretion coupling.
- Electrophysiological evidence for these Ca2+ channels has been limited.
Purpose of the Study:
- To investigate the properties of secretagogue (compound 48/80)-induced currents in rat peritoneal mast cells.
- To provide electrophysiological evidence for Ca2+ channels involved in mast cell activation.
Main Methods:
- Whole-cell and cell-attached patch-clamp recordings were used.
- Compound 48/80 was applied to stimulate mast cells.
- Ion channel currents were analyzed using varying extracellular ion concentrations (Ca2+, Ba2+, Na+) and blockers (Cd2+, EGTA).
Main Results:
- Compound 48/80 induced transient currents suppressed by Cd2+ or EGTA.
- Currents were dependent on extracellular Ca2+ or Ba2+.
- Patch-clamp analysis revealed inward Ba2+ currents with a unitary conductance of 10.5 ± 2.0 pS and identified cation-selective channels (20-45 pS) in stimulated cells.
Conclusions:
- Electrophysiological evidence supports the existence of specific Ca2+ channels in rat mast cells.
- These channels mediate Ca2+ influx during compound 48/80-induced stimulation.
- The findings clarify the role of ion channels in mast cell signaling and secretion.