Adipocyte
From Free net encyclopedia
Adipocytes are cells present in adipose tissue, specialized in storing energy as fat. There are two types of adipose tissue (white fat and brown fat), and, as a consequence, two types of adipocytes.
- White adipocytes contain large lipid droplet surrounded by a ring of cytoplasm. The nucleus is flattened and located on the periphery. The fat stored is in a semi-liquid state, and is composed primarily of triglycerides. White adipocytes secrete resistin and leptin.
- Brown adipocytes are polygonal in shape. Unlike white adipocytes, these cells have considerable cytoplasm with lipid droplets scattered throughout. The nucleus is round, and, although eccentrically located, it is not in the periphery of the cell.
The brown color come from the large quantity of mitochondria. Brown fat is also known as “baby fat,” and is used to generate heat.
Although the lineage of adipocytes is still unclear, it appears mesenchymal stem cells can differentiate into two types of lipoblasts, one that gives rise to white adipocytes and the other to brown adipocytes.