UCP1 and oxidative capacity of adipose tissue in adult ferrets ( Mustela putorius furo)

Abstract

The main mass of brown adipose tissue is located in the interscapular region in rodents, while certain species, such as humans, have a tissue that resembles the brown depot, but in different locations. Ferrets have been described as a useful model in different studies because of their similarity with humans. Here we have characterised the oxidative capacity (cytochrome c oxidase activity) and the pattern of UCP1 production in different adipose tissue depots (retroperitoneal, inguinal and interscapular) in ferrets housed at different temperatures. For this purpose adult female ferrets were divided into two groups, one housed at 22 °C and the other acclimated to 4 °C for one week. Our data show that, in 22 °C-acclimated ferrets, and unlike rodents, UCP1 is present at low levels in the different adipose tissue depots studied, with higher specific levels in the retroperitoneal than in the interscapular depot, whereas the inguinal depot has intermediate levels. Cold-exposure produces a transformation in the adipose tissue, increasing the number of brown adipocytes and UCP1 levels in the retroperitoneal and in the interscapular depots. Cytochrome c oxidase activity is also higher in the retroperitoneal depot but is not affected by cold. Due to its higher oxidative capacity and UCP1 content, the retroperitoneal adipose depot in ferrets seems to be the most important when considering a potential thermogenic role. In conclusion, in adult ferrets, UCP1 is expressed in different adipose depots and the expression of this protein is responsive to a cold-stimulus. These results suggest that ferrets could be considered as a useful animal model to approach studies of adipose tissue thermogenesis.