Erythroferrone And Hepcidin Responses Following A Single Bout Of Endurance Exercise

Hepcidin is a liver-derived hormone that plays a key role in iron regulation by suppressing iron absorption in duodenum and iron recycling from macrophages. Recent research has indicated that erythroferrone (ERFE), a hormone which is produced by erythroblasts, acts on hepatocytes to suppress hepcidin expression. It has been reported that synthesis of erythroferrone is stimulated by erythropoietin (EPO). On the other hand, ERFE has functions as a myokine induced by endurance exercise (also known as myonectin), which protects the heart from ischemic injury. However, little has been reported on the time-course changes in serum ERFE levels, and its effect in iron regulation following exercise. PURPOSE: The present study aimed to evaluate changes in serum ERFE and hepcidin levels following a single bout of endurance exercise. METHODS: Ten healthy males (22.7 ± 1.8 yrs., 173.4 ± 3.8 cm, 66.0 ± 9.7 kg) performed 60 min of treadmill running at 70% of maximal oxygen consumption. Venous blood samples were collected before (baseline), immediately after, and 1 h and 3 h after exercise. Serum ERFE, ferritin, iron, and hepcidin levels were evaluated. RESULTS: Serum hepcidin levels increased significantly 3 h after exercise compared with baseline (15.20 ± 5.73 to 42.06 ± 17.15 ng/mL, p < 0.001). However, there was no significant changes in serum ERFE (5.56 ± 0.99 to 5.51 ± 1.12 ng/mL, p > 0.05), ferritin, and iron levels immediately after exercise compared with baseline (p > 0.05). On the other hand, a negative correlation was demonstrated between serum ERFE and iron levels immediately following exercise (r = -0.677, p = 0.031). Moreover, there was a trend of inverse correlation between serum ERFE levels immediately following exercise and serum hepcidin levels 3 h after exercise (r = -0.628, p = 0.052). CONCLUSION: Although serum ERFE levels did not change significantly following a single bout of endurance exercise, the post-exercise serum ERFE levels may be related to exercise-induced iron and hepcidin elevations. Ritsumeikan University