Effect of calorie restriction and refeeding on skin wound healing in the rat

Calorie restriction (CR) is a reliable anti-aging intervention that attenuates the onset of a number of age-related diseases, reduces oxidative damage, and maintains function during aging. In the current study, we assessed the effects of CR and other feeding regimens on wound healing in 7-month-old Fischer-344 rats from a larger cohort of rats that had been fed either ad libitum (AL) or 40% calorie restricted based on AL consumption. Rats were assigned to one of three diet groups that received three skin punch wounds along the dorsal interscapular region (12-mm diameter near the front limbs) of the back as follows: (1) CR (n = 8) were wounded and maintained on CR until they healed, (2) AL (n = 5) were wounded and maintained on AL until wound closure was completed, and (3) CR rats were refed (RF, n = 9) AL for 48 h prior to wounding and maintained on AL until they healed. We observed that young rats on CR healed more slowly while CR rats refed for 48 h prior to wounding healed as fast as AL fed rats, similar to a study reported in aged CR and RF mice (Reed et al. 1996). Our data suggest that CR subjects, regardless of age, fail to heal well and that provision of increased nutrition to CR subjects prior to wounding enhances the healing process.