MgTx inhibits K⁺ currents in macrophages. Cells were held at −80 mV, and pulse potentials were applied as indicated in Fig. 1 in the presence or absence of 750 pM MgTx. (A) Current density (pA/pF) versus voltage relationship of K⁺ currents. Current density was calculated as a function of the peak amplitude and the capacitance for each recorded cell in the presence (black symbols) and absence (white symbols) of MgTx. (B) Percentage of MgTx inhibition at the peak current density (+60 mV). White bar, control; black bar, LPS; gray bar, DEX. *, P < 0.05 versus control; n = 4–6 cells per group (Student’s t test).