Outward current induced by mannan in mouse peritoneal macrophages

摘要

To define the characteristics of the phagocytic mannose receptor, the relationship between stimulation of mannose receptors by mannan and ion channel activity was analyzed by the whole cell perforated patch-clamp method. Puff application of mannan (2 mg/mL) onto peritoneal macrophages from thioglycollate-stimulated mice induced an outward current at smaller holding potentials than K+ equilibrium potentials. Reversal potentials were dependent on external K+ concentrations but not by external Cl- concentration. A K+ channel blocker, tetraethylammonium (TEA, 20 mM) partially suppressed the outward current. Ca2+-dependent K+ channel blockers, quinine (1 mM) and charybdotoxin (ChTX, 10(-6) M) markedly suppressed che outward current. The current was inhibited in Ca2+-free and 1 mM EGTA containing solution. These results suggest that stimulation of the mannose receptor, which functions as a phagocytic receptor, activates Ca2+-dependent K+ channels in mouse peritoneal macrophages. [References: 33]