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. Author manuscript; available in PMC: 2016 Jun 1.
Published in final edited form as: Free Radic Biol Med. 2015 Mar 17;83:252–261. doi: 10.1016/j.freeradbiomed.2015.02.035

Fig 4.

Fig 4

Isolated right-ventricular papillary muscles from T4-treated mice preserved their length-dependent activation, but lost their ability to respond to increased frequency or β-adrenergic stimulation. (A) Length-dependent activation. Peak isometric developed force (Fdev) value is expressed as a fraction of its corresponding Fdev at optimal length (Lopt) and presented as the mean ± SEM. (B) Force–frequency relationship. Fdev value is expressed as a fraction of its corresponding Fdev at the basal frequency of 4 Hz and presented as the mean ± SEM. (C) β-Adrenergic stimulation. Fdev value is expressed as a fraction of its corresponding Fdev at the basal frequency of 4 Hz before isoproterenol addition and presented as the mean ± SEM. Control, n=12; T4, n=11; allopurinol, n=10; apocynin, n=10; L-NIO, n=9; MitoTEMPO, n=9. +Significant change as revealed by two-way ANOVA. *Significant change as revealed by one-way ANOVA followed by Dunnett multiple comparisons post hoc test, comparing all groups to T4.