Figure 10. Pyrimidine supplementation with systemic uridine administration is associated with significantly better cardiac repair and postinjury heart function.

(A) Schematic of continuous uridine administration by a subcutaneous pump starting 1 day prior to injury and continuing for 14 days after. (B) B and M mode echocardiogram demonstrating better preservation of contractile function during diastole (green arrows) and systole (yellow arrows) in uridine-injected animals. (C) EF and fractional shortening and LV internal diameter in systole and diastole following uridine administration. n = 15 (vehicle) and n = 15 (uridine) at basal, 1 week, 2 weeks, and 3 weeks; n = 14 (vehicle) and n = 15 (uridine) at 4 weeks. (D) Pie chart demonstrating fraction of animals with mild, moderate, and severe reductions in EF following vehicle or uridine administration. (E) Masson trichrome staining demonstrating scar size (blue) at apex and midventricles of vehicle- or uridine-injected animals and (F) quantitation of differences in scar size as a fraction of the LV surface area. n = 14 (vehicle) and 15 (uridine). Scale bar: 1 mm. (G) Pie chart demonstrating fraction of animals demonstrating mild, moderate, and severe fibrosis following vehicle or uridine administration, (H) Heart weight, body weight, and HW/BW ratio in vehicle- versus uridine-treated animals. n = 14 (vehicle) and n = 15 (uridine). (I) Histology demonstrating capillaries (CD31 staining) in injured regions of hearts 4 weeks after injury in vehicle- or uridine-treated animals and (J) quantitation of capillaries. n = 14 (vehicle) and 15 (uridine). Scale bar: 10 μm. Data are represented as mean ± SEM. **P < 0.01, ordinary 2-way ANOVA with Šidák’s multiple comparisons test (C) or 2-tailed Student’s t test (F, H, and J).