Echocardiographic results and circulating levels of BUN and creatinine prior to and at 60 after CRS induction. A: By day 0, analytical result of left ventricular ejection fraction (LVEF), P>0.5. B: By the day 60, analytical result of LVEF, * vs. other groups with different symbols (†, ‡, §, ¶, #), P<0.0001. C: By day 0, the analytical result of blood urine nitrogen (BUN) level, P>0.5. D: By day 60, analytical results of BUN level, * vs. other groups with different symbols (†, ‡, §, ¶, #), P<0.0001. E: By day 0, analytical result of creatinine level, P>0.5. F: By day 60, analytical result of creatinine level, * vs. other groups with different symbols (†, ‡, §, ¶, #), P<0.0001. G: By day 60, analytical results of ratio of urine protein to creatinine, * vs. other groups with different symbols (†, ‡, §, ¶, #), P<0.0001. All statistical analyses were performed by one-way ANOVA, followed by Bonferroni multiple comparison post hoc test (n = 8 for each group). Symbols (*, †, ‡, §, ¶, #) indicate significance (at 0.05 level). SC = sham control; CKD = chronic kidney disease; CRS = cardiorenal syndrome; Mel = melatonin; Ex4 = exendin-4.