Fig. 5
Activation of TAAR1 decreases IA by targeting Kv1.4 channels. a The expression of Kv1.4, Kv3.4, Kv4.1, Kv4.2 and Kv4.3 transcripts in mouse TGs. Samples without reverse transcriptase (-RT) were used as negative controls. b through d The time course curves of IA changes induced by 0.1 µM tyramine in the presence of AmmTX3 (2 µM, n = 11 cells, b), CP339818 (1 µM, n = 9 cells, c) or UK78282 (1 µM, n = 10 cells, d). Insets in each panel indicate the representative traces. The letters indicate the points used for sample traces. e Summary data indicating the effect of tyramine on IA in the presence of AmmTX3, CP339818 or UK78282. **p < 0.01 vs. control, paired t test. f Western blot analysis demonstrating the protein abundance of Kv1.4, Kv3.4 or Kv4.3 in the control siRNA (NC-siRNA) and Kv1.4-siRNA-treated (Kv1.4-siRNA) groups. β-actin served as a loading control. The immunoblots are representative of the results of at least three independent experiments. **p < 0.01 vs. NC-siRNA, unpaired t test. g Representative traces (left panel) and bar graph (right panel) demonstrating that Kv1.4-siRNA treatment abrogated the tyramine-mediated IA reduction (n = 14 cells). Tyramine at 0.1 µM significantly decreased IA in cells transduced with NC-siRNA (n = 15 cells). *p < 0.05 vs. control + NC-siRNA, unpaired t test