Metabolic rate and nitrogen balance after skeletal trauma in female and male rats.
Unequal metabolic responses to trauma by women and men have been suggested, but an explicit investigation demonstrating this conjecture has not been made. The responses of resting energy expenditure (REE) and nitrogen balance for 3 days before and 7 days after skeletal trauma were determined for female and male rats. Food intake and body weight were recorded daily, and 24-h urine samples were collected. Baseline REE and nitrogen balance were obtained for 3 consecutive days before induction of trauma. Then rats were divided into female trauma (n = 8), male trauma (n = 7), female control (n = 8), and male control (n = 7) groups. Trauma was produced by bilateral femoral fracture to anesthetized rats. Control rats were anesthetized without skeletal trauma. Traumatized rats were fed ad libitum for 7 days, and control rats were pair fed with the traumatized rats. The results showed that REE increased and nitrogen balance decreased in traumatized male rats relative to their controls. Traumatized female rats had increased REE and unchanged nitrogen balance compared with their controls. Traumatized female rats had a larger percentage increase in REE on days 5 through 7 than did traumatized male rats. These findings demonstrate a difference between female and male rats in response to trauma. Female rats use more energy and lose less nitrogen after trauma than do male rats. The results suggest that recommendations for increased energy and protein needs after trauma should consider the sex of the subject intended to be fed.
Yang
Q
Q
Department of Surgery, Medical College of Ohio, Toledo.
Birkhahn
R H
RH
D000818:Animals; D001835:Body Weight; D004734:Energy Metabolism; D005260:Female; D005264:Femoral Fractures / Q000378:metabolism* / Q000652:urine; D008297:Male; D009584:Nitrogen / Q000652:urine*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics; D013997:Time Factors
D009584:Nitrogen