IEPA.d34.s80
Immunohistochemical localization of leptin and uncoupling protein in white and brown adipose tissue
IEPA.d34.s81
To establish the cell type expressing leptin, we also assessed the size and organization of lipid droplets, the ultrastructural features of mitochondria, and the presence or absence of uncoupling protein, a brown fat-specific marker
IEPA.d34.s82
In brown adipose tissue of lean animals, multilocular uncoupling protein (UCP)-positive brown adipocytes had typical brown mitochondria and were leptin-negative, both in fed and fasted conditions
IEPA.d34.s83
At the periphery of the interscapular brown adipose tissue depot, unilocular, UCP-negative adipocytes (mean diameter: 41.55 microns) with white-type mitochondria were observed, and these cells were leptin-positive
IEPA.d34.s84
In obese (db/db) animals, brown fat was composed mainly of small unilocular, UCP-positive adipocytes (mean diameter: 40.08 microns), which were also leptin-positive
IEPA.d34.s85
In summary, classical brown adipocytes differ from white adipocytes, not only by their morphology and UCP expression, but also by their apparent lack of detectable leptin expression