Adrenal Steroids and the Liver in the Regulation of Peripheral Fat Mobilization

¹ From the Department of Physiology, University of Chicago, Chicago, Illinois

Changes in the fat content of the epididymal fat depot of the rat were used as a measure of the rate of peripheral fat mobilization during fasting and after phlorizin treatment in the adrenalectomized rat, and after fasting and muscle work in eviscerated rats. It was found that the adrenalectomized rat maintained on 1% saline did not differ from normal controls in its ability to mobilize body fat in response to fasting or phlorizinization. It appears that the inability of the adrenalectomized animal to develop a fatty liver is not due to inadequate mobilization of fat stores. Working, intact animals given glucose show an increased fat movement out of depot fat stores. The same degree of muscle work in the eviscerate rat, however, leads to a net increase in fat deposition in the epididymal fat body after 12 hours. It is suggested that the liver in some way regulates the movement of fat from storage areas in response to changes in the caloric needs of the animal.