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Transgenic brown adipose tissue-ablated uncoupling protein diphtheria toxin A chain mice were used in the investigation of the dependence of feeding on temperature and the function of leptin in the regulation of food intake. Results reveal that the adjustment of food intake among control subjects during acclimation to cold temperature is not regulated by leptin. Further, the adjustment in food intake among transgenic mice is impaired.

The effects of impaired brown adipose tissue (BAT) thermogenesis on the progression of obesity and hyperphagia were analyzed in uncoupling protein gene (UCP)-DTA transgenic mice. BAT ablation in UCP-DTA transgenic mice under elevated thermoneutral conditions prevented the development of obesity and hyperphagia. The effects of elevated thermoneutrality in BAT-ablated transgenic mice indicated the role of BAT thermogenesis in the regulation of energy balance in mice that are exposed to temperatures below thermoneutrality.

A study of the absence of beta3-adrenoceptors and the regulation of glucose transport by insulin to guinea pig brown adipose tissue reveals the apparent absence of beta3-adrenoreceptors in brown adipocytes and a selective absence of glucose transport regulation by insulin. Brown adipocytes from the brown adipose tissue of cold-conditioned guinea pig exhibit an increase in their thermoresponsiveness to norepinephrine while the brown adipocytes from warmth-conditioned animals do not exhibit such increase. Intestines and bronchial smooth muscles exhibit the presence of beta3-adrenergic receptors.

The effects on the energy balance and brown and white adipose tissues (BAT and WAT) of young rats fed on a high fat obesity inducing diet by a highly selective B3-adrenergic agonist CL-316,243(CL) were studied. An increase in the resting metabolic rate increased the body temperature and the 24-hour energy expenditure in chronic treatment with CL. The BAT mitochondrial proliferation, thermogenesis, overall energy expenditure and leanness were increased by CL, which retarded WAT hyperplasmia development during the initial stage of diet-induced obesity.

Experimental analysis of two mice cell lines, uncoupling protein-diphtheria toxin A-chain (UCP-DTA) and attenuated mutant UCP-176, using immunoblotting techniques and UCP antisera, elucidated the correlation between brown adipose tissue (BAT) ablation and development of obesity in mice with genetically ablated BAT. BAT, which is a center of activity during thermogenesis, controls energy balance in mice and potentiates uncoupled mitochondrial respiration. Brown fat deficiency in mice leads to enhanced metabolic activity and is characterized by progressive obesity in the absence of hyperphagia.

Assesses the responsiveness of glucose transport to insulin and to adregenic agonists acting on beta1- and beta3-adregenic receptors in brown adipose tissue (BAT) in guinea pigs. Effect of cold acclimation on the responsiveness; Thermogenic capacity of BAT; Effects of NE and insulin on glucose transport in brown adipocytes.