Figure 2. ECHO and HEMO Measurements of Cardiac Functions and Evaluation of Cardiac Fibrosis in IR + Aging Model.

(A) Diagrammatic representation of the experimental design to evaluate the effect of acute low-dose, whole body 50 cGy, 1 GeV ¹H and 15 cGy, 1 GeV/n ⁵⁶Fe IR in the hearts of 8–10 months old C57BL/6NT over 10 months post-IR. IR-induced alterations in Radiation+Aging model in cardiac function were assessed by echocardiography (ECHO), hemodynamic (HEMO) and morphometric/histologic measurements and activation of signaling pathways by protein analyses. ECHO analysis of cardiac function in the hearts of full-body ¹H-IR, ⁵⁶Fe-IR and non-IR control mice 1, 3 and 10 months post-IR for: (B) Ejection Fraction - EF%, (C) Posterior wall thickness - PWth (mm). HEMO measurements and analysis of cardiac function in the hearts of full-body ¹H-IR, ⁵⁶Fe-IR and non-IR control mice 1, 3 and 10 months post-IR for: (D) LV ESP (mmHg), (E) LV EDP (mmHg), (F) LV dP/dt_Max and dP/dt_Min (mmHg/sec). (G) Graphic representation of % fibrosis in the hearts of full-body ¹H-IR, ⁵⁶Fe-IR and non-IR control mice 1, 3 and 10 months post-IR evaluated with Masson's trichrome staining. Results in all graphs (B–G) are presented as mean ± SEM; n = 6–8 animals per time point/group for non-IR control (solid black bars), ¹H-IR (solid grey bars) and ⁵⁶Fe-IR (solid white bars). Statistical significance was assigned when P<0.05.