FIGURE 3.

A, effect of LPS on membrane potentials (V_m) was studied in vascular SMCs freshly dissociated from the mouse aorta by parallel comparison of the V_m recorded from cells treated with and without LPS. Although no obvious changes in V_m were seen with an LPS treatment for 0, 2, and 6 h, significant hyperpolarization occurred with a 16 h exposure (*, p < 0.05; n = 10). B–D, enhancement of current density with LPS exposure. The current density was calculated by dividing the current amplitude by the whole cell capacitance in each cell. Without LPS, the pinacidil-activated current (I) density was ∼54% greater than the basal currents (B, n = 21, **, p < 0.01). After an overnight treatment with LPS (1 μg/ml), the density of basal currents increased by 50%, whereas the pinacidil-activated current density was further elevated by 59% (C, n = 17). K_ATP currents were isolated by subtraction of the glibenclamide-sensitive currents from the pinacidil-activated currents (Fig. 2, G and H). The K_ATP current density was significantly enhanced after LPS exposure (*, p < 0.05, D).