Alterations in Amylin and Glucagon During Prolonged Exercise

Endocrine alterations from concentric vs. eccentric muscle actions: A brief review

“…Amylin (also known as islet amyloid polypeptide, IAPP) is co-secreted from pancreatic β-cells with insulin in response to glucose [67,68] because they share a common regulatory promoter motif [69,70]. Amylin regulates blood glucose by reducing gastric emptying and inhibiting hepatic glycogenolysis [71].…”

“…Amylin is a beta-cell peptide that regulates blood glucose by inhibiting alphacell glucagon release and reducing gastric emptying [67]. In separate trials, nine young men completed CON and ECC muscle actions for bench press, leg extension, military press, and leg curl exercises at 80% of a 10-RM load.…”

“…Cortisol declined similarly for both trials suggesting that neutrophilia produced by the eccentric exercise was not associated with increases in cortisol. Typically, decline in cortisol over time during exercise in morning hours occurs due to circadian rhythm and is observed in moderately strenuous exercise, whereas high intensity exercise typically elicits increases in hypothalamicpituitary-adrenal axis activity resulting in increases in cortisol responses [86,87,88] In a study mentioned earlier, Kirwan et al [76] induced muscle damage with downhill running and compared cortisol and glucagon responses to cycling which did not produce muscle damage. Both acute cycle ergometry (primarily concentric muscle actions) and downhill running did not produce significant changes in cortisol or glucagon.…”