Fig. 7.

Block of BK channels by penitrem A augments phenylephrine-induced blood pressure responses in mice. A, mean arterial pressure and heart rate are shown for a representative mouse. The mouse received phenylephrine (0.5 μg/kg/min i.v.), which increased pressure. There was no reflex change in heart rate, because the ganglionic blocker hexamethonium (5 mg/kg i.v.) was injected before the experiment. Penitrem A (100 μg/kg/min i.v.) was added and increased pressure further. B, group data (n = 5 mice) illustrate the effect of penitrem A to augment phenylephrine-induced pressor responses. * and † indicate significant difference (p < 0.05) from control and phenylephrine, respectively, by one-way ANOVA.