Fig. 5.
KV channel current density is elevated in SMCs from TgNotch3R169C mice. (A) Families of KV currents from isolated cerebral arterial and arteriolar SMCs elicited by voltage pulses from −70 mV to +60 mV in the presence of 1 µM paxilline (included to block BK channel currents). (B) Graph summarizing the current density, calculated by dividing membrane current amplitude at the end of the pulse by cell capacitance (*P < 0.05; one-way ANOVA). (C) Activation time constants (τact) were determined from an exponential fit of individual voltage-evoked (20-mV steps) current traces in the presence and absence of 4-AP (5 mM). (D) Deactivation time constants (τdeact), obtained from an exponential fit of tail currents at −40 mV. (E) Steady-state activation properties of KV currents measured from normalized tail currents. The voltage for half-maximal activation (V0.5) and the factor k were obtained from a fit of the data to the Boltzman equation.