The exact function of osteocytes isn't known. Scientists believe they may be involved in several functions, including strengthening bones by responding to muscles working around them.
Muscle activity causes small deformation in bones. Some researchers believe that osteocytes repair these deformations, making bones stronger. They may also make bones weaker in the case of less muscular activity.
Other theories about the function of osteocytes include removing calcium from bones if the body's mineral level is too low, and that they play some sort of role in creating new bone cells. It also is believed to have the ability to function as an endocrine cell and provides soluable factors not only just to bone cells, but to body organs and tissues.
Osteocytes, which make up 90 to 95 percent of adult bone, are produced by osteoblasts, which are cells that form bone when osteoblasts become incorporated into the bone matrix. Osteocytes stay in contact with each other and with cells on the bone surface through channels called canalicul.
Osteocytes are the longest-living bone cell, surviving decades. As people age, these cells die. This contributes to bone conditions in some older adults because healthy osteocytes are necessary for proper bone function and to maintain health of other organs.