Fig. 4.

Aged Rad^−/− hearts exhibit enhanced function with progressive LV wall thickening. A: representative images of Masson's trichome-stained sections showing increasing wall thickness in Rad^−/− from 4, 8, and 21 mo. B: representative B-mode images from 4- and 18-mo-old mice. C and D: ejection fraction and fractional shortening are elevated in young and aged Rad^−/−. E: relative wall thickness (h/r) is progressively higher in Rad^−/−; n = 10–13 4-mo and 3–4 18-mo mice. *P < 0.05, **P < 0.01, ***P < 0.001,****P < 0.0001 vs. WT. F: cardiac output remains unchanged in WT and Rad^−/− mice; n = 4–5 mice per genotype. G: Rad expression is not changed in old age. Data represented as expression in 20-mo-old relative to 8-mo-old mice. Calsequestrin (CSQ) is shown as a loading control; n = 3 mice per genotype.