Effect of age and gender on thermoregulation

• DOI: 10.1152/ajpregu.1989.257.4.r700
• Publication Date: 2017-12-24T22:42:36Z
• Authors: R. B. McDonald; C. Day; K. Carlson; J. S. Stern; B. A. Horwitz
• Keywords: Thermogenin

Previous investigations have shown that during cold exposure 24-mo-old male Fischer 344 (F344) rats do not thermoregulate as well 12-mo-old animals. To determine if this deficiency also occurs in female rats, we measured oxygen consumption (thermogenesis) and colonic temperature of 5, 23, 27 mo age at rest 6 h to degrees C. In addition, nonshivering thermogenesis (NST) was evaluated from the capacity brown adipose tissue (BAT) mitochondria isolated cold-exposed bind guanosine 5'-diphosphate (GDP). Neither nor gender had a significant effect on resting or expressed mass-independent basis (l/kg body mass0.67) lean mass independent mass0.67). The drop response greater rats. However, females exhibited increased BAT relatively constant GDP binding with advancing age, whereas males showed decreased binding. Although data suggest NST rates cold-induced were similar older vs. Taken together, our indicate has impact thermoregulation that, under conditions study, involves differential heat conservation rather than production.