Figure 1.

K⁺ channel expression in AMCs derived from P0 pups born to saline-treated versus nicotine-treated dams. In A1–A3, mean (±SEM) current density versus voltage plots are shown for saline-treated AMCs exposed to control (C) and either the BK channel blocker IbTx (100 nm; n = 10) (A1), the SK channel blocker Apa (100 nm; n = 10) (A2), or the nonspecific blocker of Ca²⁺ channels cadmium (Cd²⁺) (50 μm; n = 10) (A3), which indirectly blocks Ca²⁺-dependent K⁺ channels. The insets show sample recordings at +30 mV; holding potential was −60 mV. Corresponding data for P0 nicotine-treated AMCs are shown in B1–B3 (n = 10). Note nicotine-treated AMCs expressed similar Ca²⁺-dependent K⁺ currents as saline-treated AMCs. Isolated AMCs from pups exposed to nicotine in utero also showed expression of the K⁺ channel subunits Kv1.2 and Kv1.5, BK (α-subunit), and SK2, as determined by immunofluorescence (C).