Ghrelin mediates exercise endurance and the feeding response post-exercise.
Authors Mani BK, Castorena CM, Osborne-Lawrence S, Vijayaraghavan P, Metzger NP,
Elmquist JK, Zigman JM
Submitted By Submitted Externally on 4/9/2018
Status Published
Journal Molecular metabolism
Year 2018
Date Published 3/1/2018
Volume : Pages 9 : 114 - 130
PubMed Reference 29396372
Abstract Exercise training has several well-established health benefits, including many
related to body weight, appetite control, and blood glucose homeostasis.
However, the molecular mechanisms and, in particular, the hormonal systems that
mediate and integrate these beneficial effects are poorly understood. In the
current study, we aimed to investigate the role of the hormone ghrelin and its
receptor, the growth hormone secretagogue receptor (GHSR; ghrelin receptor), in
mediating the effects of exercise on food intake and blood glucose following
exercise as well as in regulating exercise endurance capacity., We used two
mouse models of treadmill running to characterize the changes in plasma ghrelin
with exercise. We also assessed the role of the ghrelin system to influence food
intake and blood glucose after exercise, exercise endurance, and parameters
potentially linked to responses to exercise. Mice lacking GHSRs (GHSR-null mice)
and wild-type littermates were studied., An acute bout of exercise transiently
elevated plasma acyl-ghrelin. Without the action of this increased ghrelin on
GHSRs (as in GHSR-null mice), high intensity interval exercise markedly reduced
food intake compared to control mice. The effect of exercise to acutely raise
blood glucose remained unmodified in GHSR-null mice. Exercise-induced increases
in plasma ghrelin positively correlated with endurance capacity, and time to
exhaustion was reduced in GHSR-null mice as compared to wild-type littermates.
In an effort to mechanistically explain their reduced exercise endurance,
exercised GHSR-null mice exhibited an abrogated sympathoadrenal response, lower
overall insulin-like growth factor-1 levels, and altered glycogen utilization.,
Exercise transiently increases plasma ghrelin. GHSR-null mice exhibit decreased
food intake following high intensity interval exercise and decreased endurance
when submitted to an exercise endurance protocol. These data suggest that an
intact ghrelin system limits the capacity of exercise to restrict food intake
following exercise, although it enhances exercise endurance.