DIMINISHED RESPONSE TO FOOD-DEPRIVATION OF THE RAT BROWN ADIPOSE-TISSUE MITOCHONDRIAL UNCOUPLING SYSTEM WITH AGE

The aim of the present work is to investigate the effect of starvation on brown adipose tissue thermogenic activity with aging. Interscapula r brown adipose tissue from female Wistar rats of different ages was u sed; half of them were fed and the other half were starved for 24 hour s. Mitochondria were isolated and mitochondrial protein content, GDP-b inding, Cytochrome-c Oxidase activity and uncoupling protein levels we re measured. Results show a decrease of all studied parameters, indica ting a diminished thermogenic activity with age. The response to starv ation is almost the same in all the parameters studied: a general redu ction with starvation and a progressive disappearance of this response to starvation with aging. On the whole, these results would indicate a deficient regulation of brown adipose tissue thermogenic activity in old. animals, as it happens in other animal models with an alterated thermogenesis.