Effect of single bout downhill running on the serum irisin concentrations in rats

Abstract

This study aimed to characterize the effect of different running modes on serum irisin concentrations in rats. A total of 18, 10-week-old rats were divided into three groups; control group, 16° uphill running group (concentric exercise; CON) and, −16° downhill running group (eccentric exercise; ECC). The running group’s rats ran on the inclined treadmill at 16 m/min, for a total of 90 min. Blood was drawn from the rats, 48 h after running, after which the rats were anesthetized. The serum concentrations of irisin were measured using enzyme-linked immunosorbent assays. Vastus intermedius was collected for immunohistochemical analysis. After multiple comparisons, the ECC showed a significantly high serum irisin concentration (ECC: 28.42 ± 6.31 ng/ml, CON: 21.27 ± 3.03 ng/ml) and a larger irisin antibody reactive cross-sectional area in vastus intermedius compared to the CON (p < 0.05). This is the first study to reveal that single bout downhill running increases serum irisin concentrations in rats.

Keywords:

• downhill running
• eccentric contraction
• myokine
• Irisin
• myokine

Acknowledgements

The authors thank the members of the Nakajima lab for supporting the experiment.

Author contributions

Design of the work: All authors. Collection of Data: MM, IT, and NM. Analysis and interpretation of data: MM and NM.

Disclosure statement

No potential conflict of interest was reported by the author(s).