Postprandial thermogenesis of rats with glutamate induced obesity in relation to energy intake.

Postprandial thermogenesis was estimated in 4-month-old male rats with glutamate induced obesity after being fed with 300, 450 and 600 kJ/kg0.75 of a pellet diet, respectively by indirect calorimetry in computer-controlled open circuit metabolic cages over 8 h. After an intake of 600 kJ/kg0.75 (above the maintenance energy requirement) postprandial thermogenesis was significantly reduced in the obese animals to about 40% of control rats (12.0 versus 31.5 kJ/kg0.75 x 8h). It is concluded that the glutamate obese rat can be accepted as an animal model with impaired facultative thermogenesis, mainly caused by a reduction of sympathetic adrenergic activity.