Figure 6.
Veratridine-induced contractions involve activation of NaV1.6 channels. (A) Veratridine-induced contractions in NaV1.6+/+ vas deferens. The cumulative application of veratridine resulted in rhythmical contractions which were abolished rapidly by subsequent application of tetrodotoxin (TTX) (100 nM). The dashed line indicates the mean resting tone of vas deferens. (B) Trace showing how the application of veratridine (1–30 µM) resulted in little change to baseline tension of vas deferens from a NaV1.6−/− mouse. The dashed line indicates the mean resting tone of vas deferens. (C) Overall results showing veratridine (3 and 10 µM)-induced contractions in vasa deferentia from NaV1.6+/+ and NaV1.6−/− mice. The integrated areas of the veratridine-induced contractions (the last 1 min duration) were calculated (mN min mg−1). Each column indicates the mean + SD shown by vertical lines. Asterisk indicates a statistically significant difference and changes were considered significant at P < 0.05 (anova test).