Table 1.
Group (N) | Small intestinal tumors | Colon tumors | ||||||
Region | Size | Total | ||||||
Proximal | Middle | Distal | ≤1 mm | 1–2 mm | ≥ 2 mm | |||
Experiment 1 on AIN93G diet (5 – 11 wk of age) | ||||||||
Control (27) | 7.9 ± 1.4 | - | 21.3 ± 3.3 | - | - | - | 29.2 ± 4.4 | 0.6 ± 0.2 |
Exercise (28) | 4.5 ± 0.9c | - | 15.7 ± 3.0 | - | - | - | 20.2 ± 3.8b | 0.4 ± 0.1 |
Experiment 2 on High-fat diet (5 – 14 wk of age) | ||||||||
Control (19) | 4.0 ± 0.4 | 12.1 ± 1.7 | 14.7 ± 2.0 | 18.0 ± 2.4 | 8.1 ± 1.3 | 4.8 ± 0.6 | 30.8 ± 3.4 | 0.6 ± 0.2 |
Exercise (19) | 2.7 ± 0.3c | 7.3 ± 1.6c | 12.0 ± 1.4 | 15.3 ± 1.9 | 4.4 ± 0.9c | 2.3 ± 0.4 d | 22.0 ± 2.8c | 0.4 ± 0.1 |
a Results of Experiments 1 and 2. In Experiment 1, the small intestine was divided into two segments (proximal and distal), and the tumor size was not scored because the majority of tumors in 11-week-old mice were ~1 mm in diameter. The number of mice was accumulated from 4 identical experiments that were done with smaller numbers of mice per group. Data were then combined and analyzed through a statistical adjustment; the effects of two factors, treatment (exercise) and experiment, as well as the interaction of treatment and experiment, on the response variable, total small intestinal tumor numbers (square-rooted to stabilize the variance), were initially assessed by two-way ANOVA; factors found not to affect the response variable significantly were excluded in the final statistical analyses. bA statistically significant treatment (exercise) effect was found (p < 0.05). In Experiment 2, the small intestine was divided into three segments (proximal, middle and distal), and the tumor size was scored Each value represents mean ± SE of number of mice (N). c: p ≤ 0.05 by two-tailed t-test;d: p < 0.005 by two-tailed t-test.