Share this article on:

Exercise and Intestinal Polyp Development in APCMin Mice

COLBERT, LISA H.1 2; MAI, VOLKER2; PERKINS, SUSAN N.2; BERRIGAN, DAVID2; LAVIGNE, JACKIE A.2; WIMBROW, HEATHER H.2; GREGORY ALVORD, W.3; HAINES, DIANA C.4; SRINIVAS, POTHUR2; HURSTING, STEPHEN D.2

Medicine & Science in Sports & Exercise: October 2003 - Volume 35 - Issue 10 - p 1662-1669
doi: 10.1249/01.MSS.0000089349.54813.41
BASIC SCIENCES: Original Investigations

COLBERT, L. H., V. MAI, S. N. PERKINS, D. BERRIGAN, J. A. LAVIGNE, H. H. WIMBROW, W. G. ALVORD, D. C. HAINES, P. SRINIVAS, and S. D. HURSTING. Exercise and Intestinal Polyp Development in APCMin Mice. Med. Sci. Sports Exerc., Vol. 35, No. 10, pp. 1662–1669, 2003.

Purpose Epidemiological evidence suggests that physical activity protects against colon cancer. We previously used a mouse predisposed to intestinal polyps (APCMin) to evaluate this association and found the suggestion of fewer polyps in exercised males but not females. The present study was designed to further explore the potential exercise × sex interaction on polyp development and to begin to look at potential mechanisms.

Methods Six-week-old APCMin mice (N = 60 males; 60 females) were randomly assigned to one of two groups by sex: treadmill running at 20 m·min−1, 5% grade, 45 min·d−1, 5 d·wk−1 (EX) or nonrunning controls (CON) (N = 30 per group). EX mice ran in running wheels while in quarantine (weeks 0–3), followed by treadmill running weeks 3–8. Body weights were measured weekly. Urine was collected at 5 wk and fasting blood at 7.5 wk. Body composition was measured, serum was frozen, and polyp number and size were measured at sacrifice.

Results EX resulted in lower body weights (P < 0.01) and reduced fat mass (P < 0.01). Fasting glucose was lower in EX (P < 0.01), and leptin was lower in EX (P = 0.05) compared with CON. EX did not affect serum insulin-like growth factor-1 or urinary corticosterone. Total polyp number and size were not statistically different between groups; however, there were fewer jejunal polyps in EX (3.6 ± 0.7, mean ± SE) versus CON males (5.2 ± 0.8; P = 0.04) and an even larger difference when only the consistent runners were kept in the analysis (2.7 ± 0.5 in EX; P = 0.01).

Conclusion Despite favorable changes in body composition, blood glucose, and leptin, 8 wk of running resulted in only minor changes related to polyp development in male but not female APCMin mice.

1National Institute on Aging, and

2National Cancer Institute, Bethesda, MD; and

3Data Management Services and

4SAIC Frederick, National Cancer Institute at Frederick, Frederick, MD

Address for correspondence: Lisa Colbert, 2000 Observatory Drive, Madison, WI 53706; E-mail: lhcolbert@education.wisc.edu.

Submitted for publication December 2002.

Accepted for publication June 2003.

Copyright © 2003 U.S. Government

©2003The American College of Sports Medicine