Effect of running training on DMH-induced aberrant crypt foci in rat colon.
OBJECTIVE
We examined the effects of treadmill-running training on the induction of aberrant crypt foci (ACF), which is the first step of colon cancer induction, in the colonic mucosa of rats injected with 1,2-dimethylhydrazine (DMH).


METHODS
Four-week-old F344 rats (N = 38) were randomly assigned to training (19 rats) and control (19 rats) groups. After a week, all rats were given DMH (20 mg.kg(-1) body weight) once a week for 2 wk. Running training was started at age 7 wk (speed: 10 m.min(-1), 0% grade, 120 min.d(-1), 5 d.wk(-1)). After 4 wk of training, the rats were sacrificed and the colon was removed, opened, and counted for ACF with 0.2% methylene blue staining.


RESULTS
Running training resulted in lower body- (P < 0.01) and adipose fat weight (P < 0.05). The numbers of ACF and total AC were significantly lower in the running training group than in the control group (P < 0.05). The occurrences of one, three, and five aberrant crypts per focus were also significantly lower in the running training group than in the control group (P < 0.05). The ratios of total AC/ACF did not significantly differ between the running training and control groups.


CONCLUSIONS
The results of the present investigation suggest that low-intensity running training inhibits the DMH-induced initiation of colon ACF development.
Fuku
Noriyuki
N
Division of Health Promotion and Exercise, National Institute of Health and Nutrition, 1-23-1 Toyama, Shinjuku City, Tokyo 162-8636, Japan.
Ochiai
Masako
M
Terada
Shin
S
Fujimoto
Eri
E
Nakagama
Hitoshi
H
Tabata
Izumi
I
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000473:pathology*; D004111:Dimenhydrinate / Q000008:administration & dosage*; D005080:Exercise Test; D007564:Japan; D011230:Precancerous Conditions / Q000139:chemically induced / Q000473:pathology*; D051381:Rats
D004111:Dimenhydrinate