Adipocytes contain droplets of stored fat (triglycerides) that can be used for energy. These cells swell or shrink depending on whether fat is being stored or used. Other types of cells that comprise adipose tissue include fibroblasts, white blood cells, nerves, and endothelial cells.dipocytes are derived from precursor cells that develop into one of three types of adipose tissue: white adipose tissue, brown adipose tissue, or beige adipose tissue. The majority of adipose tissue in the body is white.