The Role of Hypothalamic Tri-Iodothyronine Availability in Seasonal Regulation of Energy Balance and Body Weight

Figure 2

Effects of intrahypothalamic microimplants releasing tri-iodotyronine (T3) on body weight (left) and epididymal weight (right) in hamsters transferred to short days (SD+T3). Hamsters receiving sham implants were also transferred to short days (SD sham) or maintained in long days (LD sham). Note that SD induced weight loss, reflecting a reduction of white fat depots as compared to hamsters maintained in LD, but that implants which increased hypothalamic T3 concentrations blocked this SD-induced catabolic response. Modified from Barrett et al. [2].