Adipocyte

Overview

Adipocytes are the cells that primarily compose adipose tissue, specialized in storing energy as fat.

Description

There are two types of adipose tissue, white adipose tissue (WAT) and brown adipose tissue (BAT), which are also known as white fat and brown fat, respectively, and comprise two types of fat cells:

• White fat cells (also known as Unilocular Cells) contain a 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 and cholesterol ester. White fat cells secrete resistin, adiponectin, and leptin.

• Brown fat cells (also known as Multilocular Cells) are polygonal in shape. Unlike white fat cells, 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 comes from the large quantity of mitochondria. Brown fat, also known as "baby fat," is used to generate heat.

Lineage

Although the lineage of adipocytes is still unclear, Preadipocytes are undifferentiated fibroblasts that can be stimulated to form adipocytes.

Mesenchymal stem cells can differentiate into adipocytes, connective tissue, muscle or bone.

Areolar connective tissue is composed of adipocytes.

External links

• Histology image: 08201loa – Histology Learning System at Boston University - "Connective Tissue: unilocular (white) adipocytes "
• Histology image: 04901lob – Histology Learning System at Boston University - "Connective Tissue: multilocular (brown) adipocytes"