VOLUNTARY RUNNING IN MALE S5B P1RAS RATS FED HIGH-FAT OR HIGH-CARBOHYDRATE DIETS/

Nineteen week-old male S5B/PlRas (S5B) rats were randomly assigned to one of 4 groups as follows: (a) activity wheel access (running)/high f at diet (RF); (b) no activity wheel access (non-running)/high fat diet (NRF); (c) activity wheel access (running)/high carbohydrate diet (RC ); and (d) no activity wheel access (non-running)/high carbohydrate di et (NRC) for the seven weeks duration of the experiment. Throughout th e 7 wk of the experiment, rats ran more during subsequent weeks than t hey did the previous week. RC rats ran more than RF rats as measured b y the running slopes. All groups of rats lost weight at the initiation of the experiment but significantly more weight was lost by running r ats than their nonrunning counterparts. The inguinal, epididymal and p erirenal/retroperitoneal (P/R) fat depots weighed significantly less i n the running than in the nonrunning groups. From among the 3 fat depo ts, the difference was greatest in the P/R depot. There were no diet o r voluntary activity effects on plasma corticosterone concentrations e xcept at week 2 when running rats had higher concentrations than nonru nning rats.