Difference in induction of uncoupling protein genes in adipose tissues between young and old rats during cold exposure

Abstract

Induction of uncoupling protein (UCP) genes in adipose tissues from young and old rats exposed to cold was compared. UCP1 mRNA expression in brown adipose tissue (BAT) was enhanced in both young and old rats after cold exposure, but the expression was downregulated at 72 h after the exposure only in the young rats. The UCP2 gene was induced notably in BAT of young rats instead of the downregulation of the UCP1 gene, whereas the induction in old rats was almost blunted. The pattern of UCP3 expression was similar to that of UCP1 expression in each group. The effect of cold exposure on the expression of UCP2 genes was also observed in white adipose tissue from the young rats. These results indicate a change in induction of UCP genes in adipose tissues with aging.