Role of Type 2 Deiodinase in Hypothalamic Control of Feeding Behavior - Abstract
The amount of energy in the body is highly regulated. The hypothalamus is a key
neural structure involved in this process, keeping the intake of food in step with the
energy expenditure. The main hypothalamic nuclei involved in energetic metabolism
regulation are the arcuate, periventricular, dorsomedial and ventromedial that
integrates several peripheral signals, such as leptin and adiponectin. Although is well
known that T3 regulates basal metabolism, it also has an important role in feeding
behavior regulation since it stimulates neurons that express orexigenic neuropeptides,
such as AgRP and NPY found in the arcuate hypothalamic nuclei. The amount of T3
available in the brain depends on the activity of the type 2 deiodinase (D2) that
transforms T4 in T3. D2 is expressed in glial cells that are in close contact with the
AgRP/NPY expressing neurons in the arcuate hypothalamic nuclei, suggesting that D2
has an important role in the regulation of the feeding behavior and in the body weight.