Figure 3: Effects of Ang II on AP Morphology and Hyperpolarization-Activated Current (I

(A) Representative spontaneous AP recordings in wild-type and NPR-C−/− SAN myocytes treated with saline or Ang II. (B, C) Summary data illustrating cycle length (B) and DD slope (C) in wild-type and NPR-C−/− mice treated with saline or Ang II. *p < 0.001 versus saline; p = 0.557 for AP cycle length and p = 0.517 for DD slope between genotypes within treatment group; n = 16 cells for wild type/saline, 11 cells for wild type/Ang II, 10 cells for NPR-C−/−/saline, and 13 cells for NPR-C−/−/Ang II for AP data. See Supplemental Table S2 for additional AP parameters. (D) Representative If recordings in SAN myocytes isolated from wild-type and NPR-C−/− mice treated with saline or Ang II. (E) (F) Summary If IV curves for wild-type (E) and NPR-C−/− (F) mice treated with saline or Ang II. *p < 0.001 versus saline at each membrane potential by 2-way repeated-measures analysis of variance with Tukey post-hoc test. (G, H) If activation curves for wild-type (G) mice and NPR-C−/− (H) mice treated with Ang II. See Supplemental Figure S4 for additional If kinetic analysis. n = 17 cells for wild type/saline, 13 cells for wild type/Ang II; 13 cells for NPR-C−/−/saline, and 16 cells for NPR-C−/−/Ang II. IV = current voltage relationship; pA = picoamperes; pF = picofarads; other abbreviations as in Figures 1 and 2.