Extended Data Fig. 4: AMVM contractility after 5 weeks of different dietary regimens and functional characterization and analysis of the IRE1α–XBP1 axis in ZSF1-obese 20-week-old rats.
From: Nitrosative stress drives heart failure with preserved ejection fraction
a, Baseline sarcomere length. n = 4 mice and n = 35 cells per chow group; n = 3 mice and n = 30 cells per HFD group; n = 3 mice and n = 30 cells per l-NAME group; n = 3 mice and n = 31 cells per HFD + l-NAME group. b, Time to peak. n = 4 mice and n = 36 cells per chow group; n = 3 mice and n = 30 cells per HFD group; n = 3 mice and n = 30 cells per l-NAME group; n = 3 mice and n = 31 cells per HFD + l-NAME group. c, Maximum return velocity. n = 4 mice and n = 36 cells per chow group; n = 3 mice and n = 29 cells per HFD group; n = 3 mice and n = 30 cells per l-NAME group; n = 3 mice and n = 31 cells per HFD + l-NAME group. d, Change (Δ) in sarcomere length compared to baseline. n = 4 mice and n = 36 cells per chow group; n = 3 mice and n = 30 cells per HFD group; n = 3 mice and n = 30 cells per l-NAME group; n = 3 mice and n = 31 cells per HFD + l-NAME group. e, Maximum departure velocity. n = 4 mice and n = 35 cells per chow group; n = 3 mice and n = 30 cells per HFD group; n = 3 mice and n = 29 cells per l-NAME group; n = 3 mice and n = 28 cells per HFD + l-NAME group. f, Representative tracings of cardiomyocyte contraction–relaxation during pacing. Each trace depicts one cell representative of the average for each experimental group. g–k, Measurements in 20-week old WKY and ZSF1-obese rats. g, Body weight. h, Percentage LVEF. i, Ratio between mitral E wave and A wave. j, Ratio between mitral E wave and E′ wave. k, Ratio between heart weight and tibia length. l, Lung weight to tibia length ratio. g–i, l, n = 5 rats per group; k, n = 5 rats per WKY group and n = 4 rats per ZSF1-obese group. m, Electrophoretic analysis of spliced and unspliced Xbp1 transcripts in left ventricular samples from WKY and ZSF1-obese rats. Tunicamycin-treated NRVMs were used as positive control. n = 3 rats per group. n, Xbp1s mRNA levels in the left ventricles of WKY and ZSF1-obese rats. n = 5 rats per group. o, Immunoblots of p-IRE1α, IRE1α and GAPDH from left ventricular samples of WKY and ZSF1-obese rats. n = 5 rats per group. p, Densitometric analysis of the ratio of p-IRE1α to IRE1α bands. n = 5 rats per group. Data are mean ± s.e.m. a–e, One-way ANOVA followed by Sidak’s multiple-comparisons test. g–l, n, p, Two-tailed unpaired Student’s t-test. Numbers above square brackets show significant P values. For gel source data, see Supplementary Fig. 1.
