Rapid transformation of white adipocytes into fat-oxidizing machines.

ABSTRACT: Adenovirus-induced hyperleptinemia rapidly depletes body fat in normal rats without increasing free fatty acids and ketogenesis, implying that fat-storing adipocytes are oxidizing the fat. To analyze the ultrastructural changes of adipocytes accompanying this functional transformation, we examined the fat tissue by electron microscopy. After 14 days of hyperleptinemia, adipocytes had become shrunken, fatless, and encased in a thick basement-membrane-like matrix. They were crowded with mitochondria that were much smaller than those of brown adipocytes. Their gene expression profile revealed striking up-regulation of peroxisome proliferator-activated receptor gamma coactivator 1alpha (an up-regulator of mitochondrial biogenesis not normally expressed in white fat), increased uncoupling prote

SUBMITTER: Orci L 

PROVIDER: S-EPMC357051 | biostudies-literature | 2004 Feb

REPOSITORIES: biostudies-literature