TY - JOUR
T1 - Metabolic Effects of Chronic T3 Administration in the Hypothalamic Paraventricular and Ventromedial Nucleus in Male Rats
AU - Zhang, Zhi
AU - Foppen, Ewout
AU - Su, Yan
AU - Bisschop, Peter H.
AU - Kalsbeek, Andries
AU - Fliers, Eric
AU - Boelen, Anita
PY - 2016
Y1 - 2016
N2 - Thyroid hormone is a key regulator of energy metabolism. Apart from its direct effects on peripheral metabolism, thyroid hormone exerts acute metabolic effects via distinct nuclei within the hypothalamus. Recently we developed a method for chronic and local intrahypothalamic T3 administration in rats. The present study evaluated the metabolic effects of T3 delivered during either 7 or 28 days to the paraventricular or ventromedial nucleus of the hypothalamus (PVN or VMH). T3 administration for 7 days in the PVN decreased only plasma T3. There were no effects on body weight, food intake, plasma glucose concentrations, energy expenditure, locomotor activity, and respiratory exchange rate. In the liver and brown adipose tissue (BAT), there were no changes in mRNA expression of genes involved in glucose metabolism and thermogenesis. T3 administration for 7 days in the VMH did not change any of these parameters. T3 administration for 28 days in the PVN decreased food intake without affecting body weight, glucose concentrations, and body temperature. Liver and BAT gene expression was unaltered, except for decreased liver Dio1 mRNA. T3 administration for 28 days in the VMH did not affect liver and BAT mRNA expression, body weight, food intake, and body temperature, whereas blood glucose concentrations were slightly lower. In conclusion, we showed that chronic T3 administration to the PVN or VMH does not affect energy metabolism in a major way. Our results imply that the effects of intrahypothalamic T3 administration on metabolism largely depend on the duration of treatment
AB - Thyroid hormone is a key regulator of energy metabolism. Apart from its direct effects on peripheral metabolism, thyroid hormone exerts acute metabolic effects via distinct nuclei within the hypothalamus. Recently we developed a method for chronic and local intrahypothalamic T3 administration in rats. The present study evaluated the metabolic effects of T3 delivered during either 7 or 28 days to the paraventricular or ventromedial nucleus of the hypothalamus (PVN or VMH). T3 administration for 7 days in the PVN decreased only plasma T3. There were no effects on body weight, food intake, plasma glucose concentrations, energy expenditure, locomotor activity, and respiratory exchange rate. In the liver and brown adipose tissue (BAT), there were no changes in mRNA expression of genes involved in glucose metabolism and thermogenesis. T3 administration for 7 days in the VMH did not change any of these parameters. T3 administration for 28 days in the PVN decreased food intake without affecting body weight, glucose concentrations, and body temperature. Liver and BAT gene expression was unaltered, except for decreased liver Dio1 mRNA. T3 administration for 28 days in the VMH did not affect liver and BAT mRNA expression, body weight, food intake, and body temperature, whereas blood glucose concentrations were slightly lower. In conclusion, we showed that chronic T3 administration to the PVN or VMH does not affect energy metabolism in a major way. Our results imply that the effects of intrahypothalamic T3 administration on metabolism largely depend on the duration of treatment
U2 - https://doi.org/10.1210/en.2016-1397
DO - https://doi.org/10.1210/en.2016-1397
M3 - Article
C2 - 27533888
SN - 0013-7227
VL - 157
SP - 4076
EP - 4085
JO - Endocrinology
JF - Endocrinology
IS - 10
ER -