TY - JOUR
T1 - The long-term regulation of food intake and body weight depends on the availability of thyroid hormones in the brain
AU - Alva-Sánchez, Claudia
AU - Pacheco-Rosado, Jorge
AU - Fregoso-Aguilar, Tomás
AU - Villanueva, Iván
PY - 2012
Y1 - 2012
N2 - OBJECTIVES: We evaluated the contribution of the thyroid hormones to the long-term maintenance of feeding behavior and body weight, while distiguishing their direct central effects from those resulting from the metabolic rate in the peripheral tissues. METHODS: We assessed the effect of hypothyroidism on the long-term (6 months) regulation of food intake, body weight, and energy expenditure in rats. We then generated the recovery of a euthyroid condition in the brain while maintaining a low T3 availability for the peripheral organs, i.e. a combined condition of central euthyroidism with peripheral hypothyroidism, with the aid of a pharmacological combination. RESULTS: Hypothyroidism caused a decrease in the daily food intake, body weight, and body temperature. The food intake and body temperature stabilized at a lower value, whereas body weight kept decreasing at a constant rate. The administration of exogenous T4 increased food intake and body-weight gain, but had no effect on body temperature. CONCLUSIONS: The thyroid hormones are necessary for the long-term regulation of energy intake, storage, and expenditure by different mechanisms. The feeding behavior seems to be partially dependent on a direct action of the thyroid hormones on the brain and this effect is independent of the energy expenditure in the peripheral organs. The body weight is closely dependent on the thyroid status and its maintenance seems to involve thyroid action on mechanisms other than feeding and metabolic rate.
AB - OBJECTIVES: We evaluated the contribution of the thyroid hormones to the long-term maintenance of feeding behavior and body weight, while distiguishing their direct central effects from those resulting from the metabolic rate in the peripheral tissues. METHODS: We assessed the effect of hypothyroidism on the long-term (6 months) regulation of food intake, body weight, and energy expenditure in rats. We then generated the recovery of a euthyroid condition in the brain while maintaining a low T3 availability for the peripheral organs, i.e. a combined condition of central euthyroidism with peripheral hypothyroidism, with the aid of a pharmacological combination. RESULTS: Hypothyroidism caused a decrease in the daily food intake, body weight, and body temperature. The food intake and body temperature stabilized at a lower value, whereas body weight kept decreasing at a constant rate. The administration of exogenous T4 increased food intake and body-weight gain, but had no effect on body temperature. CONCLUSIONS: The thyroid hormones are necessary for the long-term regulation of energy intake, storage, and expenditure by different mechanisms. The feeding behavior seems to be partially dependent on a direct action of the thyroid hormones on the brain and this effect is independent of the energy expenditure in the peripheral organs. The body weight is closely dependent on the thyroid status and its maintenance seems to involve thyroid action on mechanisms other than feeding and metabolic rate.
KW - Body-weight regulation
KW - Feeding behavior
KW - Food intake
KW - Long term
KW - Methimazole
KW - PTU
KW - Pharmacological hypothyroidism
KW - Thyroid hormones
KW - Thyroxine
UR - http://www.scopus.com/inward/record.url?scp=84874746910&partnerID=8YFLogxK
M3 - Artículo
SN - 0172-780X
VL - 33
SP - 703
EP - 708
JO - Neuroendocrinology Letters
JF - Neuroendocrinology Letters
IS - 7
ER -