Endocrine Abstracts

The thermogenic activity of brown adipose tissue (BAT) may be a major determinant of energy balance and thus of obesity versus slimness. The acute and chronic regulation of BAT may therefore be a significant issue in body weight control. From a classical aspect where BAT is only controlled by nervous input, we see today a growing array of factors that have been forwarded as being physiologically important regulators. These factors include both classical hormones such as thyroi...

There are many effects on adipose tissue metabolism of housing mice at different temperatures. Considering the situation from a thermoregulatory perspective, it may – in retrospect – be evident that one cannot expect to observe any effect of e.g. UCP1 ablation under “normal housing” conditions. This is because at normal animal house conditions (≈20 °C), the mice experience significant cold, and they must increase their metabolism by 50-100 % (as ...

In rodents, brown adipose tissue is known to be a metabolically highly active organ. This concerns rates of blood flow, capacity for oxygen consumption and rates of uptake of lipid and carbohydrate substrates. The high rates of metabolism are dependent on stimulation of the tissue by norepinephrine, released from sympathetic neurons innervating the tissue. Following stimulation, thermogenesis occurs as a result of activation of the uncoupling protein UCP1 in the inner membrane...

Brown adipose tissue was classically a tissue with scientifically interesting bioenergetic features, manifest by the unique presence of uncoupling protein-1 in only this tissue – but it was considered to have no metabolic significance for adult humans. The acceptance within the last years of its presence in adult humans has intensified interest in its potential ability not only to keep us warm but particularly to burn excess energy, i.e. to keep us slim, and – throug...

The advent of mice as the most common animal used for metabolic studies was caused by the possibility to perform gene manipulations in this species (which first very recently has become possible in the previously most studied animal: the rat). Although the mouse in many ways would seem just to be a smaller version of the rat, the smaller size indirectly has added a confounding factor to interpretation of metabolic studies. The reason is that the environmental temperatures unde...