title: Negative energy balance induced by voluntary wheel running inhibits polyp development in APCMin mice.
abstract: Treadmill running of approximately 0.9 km/day has had inconsistent effects on spontaneous intestinal polyp development in C57BL/6J-Apc(Min)/J (Min) mice; the amount of energy expenditure and/or a lack of hormonal changes could account for this variability. The purpose of this study was to examine the effects of a negative energy balance induced by voluntary wheel running on polyps, insulin-like growth factor-1 (IGF-1) and corticosterone in Min mice. Seven-week-old male Min mice were randomly assigned to control (CON, n = 23) or wheel running (EX, n = 24) conditions for a 10-week study period. All mice had water and AIN-76A diet ad libitum for the first approximately 3 weeks on study, after which the EX group was pair-fed to the CON group to maintain a negative energy balance due to the exercise. EX mice voluntarily ran 3.8 km/day (2.7-6.0 km/day) (median, interquartile range) and weighed less than CON mice throughout the study. More CON mice died before the end of the study versus EX mice (26 versus 0%, P < 0.01). CON mice had significantly more polyps versus EX mice (21.6 +/- 1.5 versus 16.9 +/- 2.0, P < 0.01; mean +/- SE), and daily running distance in EX was inversely correlated with total polyp number (r = -0.70, P < 0.01). Urinary corticosterone output (P < 0.01) and serum IGF-1 were significantly higher in EX than CON (P < 0.001); however, total polyp number was unrelated to corticosterone (r = 0.05, P = 0.84) and IGF-1 (r = -0.01, P = 0.93). In this study, a negative energy balance produced by wheel running exercise and restricted feeding decreased polyp burden in male Min mice and appeared to have a dose-response effect on polyp number. Although EX affected IGF-1 and corticosterone, neither marker was related to total polyp number.
authors.affiliation: Department of Kinesiology, University of Wisconsin Madison, WI, USA. lhcolbert@education.wisc.edu
authors.forename: Lisa H
authors.initials: LH
authors.lastname: Colbert
authors.forename: Volker
authors.initials: V
authors.lastname: Mai
authors.forename: Janet A
authors.initials: JA
authors.lastname: Tooze
authors.forename: Susan N
authors.initials: SN
authors.lastname: Perkins
authors.forename: David
authors.initials: D
authors.lastname: Berrigan
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Hursting
mesh_terms: D000818:Animals; D001823:Body Composition; D001835:Body Weight; D003345:Corticosterone / Q000097:blood; D004734:Energy Metabolism; D017491:Genes, APC / Q000502:physiology*; D006400:Hematocrit; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007417:Intestinal Polyps / Q000517:prevention & control*; D008297:Male; D051379:Mice; D010805:Physical Conditioning, Animal; D012420:Running
chemical_list: D007334:Insulin-Like Growth Factor I; D003345:Corticosterone