Adipocyte

An adipocyte is a fat storage cell.

These morphology of these cells is round with a diameter of up to 150 micrometres. They are contained in adipose tissue (fat tissue). The following can be distinguished:

• white adipocytes contain a large lipid droplet ,
• and brown adipocytes contain many small lipid droplets and mitochondria rich in cytochromes (which gives them their brown colour).

The role of adipocytes is to accumulate energy in the form of triglyceride fat. They synthesise triglycerides from fatty acids and glycerol and also excrete them if the body needs to use its reserves.

It can also secrete hormones such as resistin and leptin which regulate appetite and allow the body to adapt to ambient temperature by thermogenesis.

The number of adipocytes increases until adolescence and then remains constant. Adipocytes in weight gain firstly increase in volume before increasing in number if weight gain is significant. Conversely, the number of adipocytes does not fall with weight loss, which facilitates weight increasing again.