Physiology&Behavior,Vol. 48, pp. 339-342. ©Pergamon Press plc, 1990. Printed in the U.S.A.
0031-9384/90 $3.00 + .00
Suppression of Food Deprivation-Induced High-Rate Wheel Running in Rats D O U G L A S P. B O E R , .1 W. F R A N K E P L I N G , * W. D A V I D P I E R C E t A N D J A M E S C. R U S S E L L * 2
Departments of *Psychology, tSociology and $Surgery The University of Alberta, Edmonton, Alberta, Canada R e c e i v e d 13 N o v e m b e r 1989
BOER, D. P., W. F. EPLING, W. D. PIERCE AND J. C. RUSSELL. Suppression of food deprivation-inducedhigh-rate wheel running in rats. PHYSIOL BEHAV 48(2) 339-342, 1990.--To test for involvement of endogenous opioids in the maintenance of high-rate running we have administered naloxone, a specific opioid antagonist, to rats. The animals were stabilized voluntarily running 6000 to 8000 m/day through a standard protocol and maintained in this state on approximately 18 g of food per day. Naloxone (50 mg/kg in saline) or saline alone was injected intraperitoneally on alternate days for 20 days. All rats ran less on days when naloxone was administered. The mean distance run for the group (N = 6, mean ---SE) was: saline: 6401 _ 985; naloxone: 5344 ___805 m/day. This difference was highly significant (p0.05) decrease in running. Inhibition of running was highly significant after eight hours (30%, p
0031-9384/90 $3.00 + .00
Suppression of Food Deprivation-Induced High-Rate Wheel Running in Rats D O U G L A S P. B O E R , .1 W. F R A N K E P L I N G , * W. D A V I D P I E R C E t A N D J A M E S C. R U S S E L L * 2
Departments of *Psychology, tSociology and $Surgery The University of Alberta, Edmonton, Alberta, Canada R e c e i v e d 13 N o v e m b e r 1989
BOER, D. P., W. F. EPLING, W. D. PIERCE AND J. C. RUSSELL. Suppression of food deprivation-inducedhigh-rate wheel running in rats. PHYSIOL BEHAV 48(2) 339-342, 1990.--To test for involvement of endogenous opioids in the maintenance of high-rate running we have administered naloxone, a specific opioid antagonist, to rats. The animals were stabilized voluntarily running 6000 to 8000 m/day through a standard protocol and maintained in this state on approximately 18 g of food per day. Naloxone (50 mg/kg in saline) or saline alone was injected intraperitoneally on alternate days for 20 days. All rats ran less on days when naloxone was administered. The mean distance run for the group (N = 6, mean ---SE) was: saline: 6401 _ 985; naloxone: 5344 ___805 m/day. This difference was highly significant (p0.05) decrease in running. Inhibition of running was highly significant after eight hours (30%, p
