A Novel Role for Adipose Tissue in Exercise‐Induced Improvements in Glucose Homeostasis

Abstract

Exercise training improves whole body glucose homeostasis, effects largely attributed to adaptations to skeletal muscle; however, training also affects other tissues including adipose tissue. We used a transplantation model to test the hypothesis that adaptations to adipose tissue contribute to training‐induced improvements in glucose homeostasis. Mice were trained for 11 days or were sedentary, and subcutaneous (SubQ) or visceral adipose tissue was transplanted into the visceral cavity of sedentary recipients. Nine days after transplant, mice receiving SubQ adipose tissue from trained mice had improved glucose tolerance compared to mice transplanted with SubQ adipose tissue from sedentary mice and Sham‐operated mice. There was no effect of transplanting visceral adipose tissue. Transplantation of SubQ adipose tissue from trained mice for longer periods (12 wks) abolished the detrimental effects of high fat feeding on glucose homeostasis and obesity. Morphological and gene array analyses revealed numerous adaptations to trained SubQ adipose tissue, most notably, the development of metabolically active brown fatlike adipocytes within the SubQ adipose tissue. Exercise training results in adaptations to SubQ adipose tissue that result in profound metabolic improvements, demonstrating a previously unrecognized role for adipose tissue in the beneficial effects of exercise on glucose homeostasis.