Abstract des Autors

The purpose of this study was to examine the effect of moderate treadmill exercise on the development of prostate cancer in rats. A secondary objective was to find out if animals were homogeneous in their response to a given exercise intensity. Forty male Lobund-Wistar rats were randomly assigned to treadmill exercise (TE; n=20) or control (C; n=20) groups. Treadmill exercise consisted of running on a motor-driven treadmill at 20 m/min (73.4+/-13.1% VO2max), 15 min daily, 3 times weekly for 6 weeks. Following the 6-week period, all animals were inoculated with 1x10**6 transplantable rat prostate cancer (PA-III) cells, subcutaneously on the back above the sacral region (Day 0). The TE group exercised two more weeks post-inoculation. Maximum VO2 did not change in either group during the initial 6-week training period, nor was it different between groups at either time, mean values ranging from 64.4+/-4.6 to 66.0+/-4.4 ml/min/kg. The numbers of rats displaying tumour on Day 30, were in groups TE and C alike (20 and 18, respectively). The total tumour volumes and numbers of lung metastatic lesions, determined on Days 30 and 45 (n=10 each) did not differ between groups. In the TE group, the post-training maximum treadmill time and body mass was negatively correlated (r=-0.687; P<0.05) while training intensity and the number of lung metastatic lesions - positively (r=0.691; P<0.05). The treadmill exercise protocol was not sufficient to elicit a training response and had no significant effect on the incidence or growth of prostate cancer in rats although animals which exercised at the highest intensity had the greatest number of lung metastatic lesions. It appears that rodents may not be homogeneous in their response to a given load. Verf.-Referat