Osteocalcin


 * Not to be confused with is_associated_with::Osteonectin or is_associated_with::Osteopontin.

Osteocalcin, also known as bone gamma-carboxyglutamic acid-containing protein (BGLAP), is a noncollagenous is_associated_with::protein found in bone and is_associated_with::dentin. Because it has is_associated_with::gla domains, its synthesis is is_associated_with::vitamin K dependent. In humans, the osteocalcin is encoded by the BGLAP is_associated_with::gene. Its receptor is is_associated_with::GPRC6A.

Function
Osteocalcin is secreted solely by is_associated_with::osteoblasts and thought to play a role in the body's metabolic regulation and is pro-osteoblastic, or bone-building, by nature. It is also implicated in bone mineralization and calcium ion homeostasis. Osteocalcin acts as a is_associated_with::hormone in the body, causing is_associated_with::beta cells in the is_associated_with::pancreas to release more is_associated_with::insulin, and at the same time directing is_associated_with::fat cells to release the hormone is_associated_with::adiponectin, which increases sensitivity to insulin.

Osteocalcin acts on is_associated_with::Leydig cells of the is_associated_with::testis to stimulate is_associated_with::testosterone biosynthesis and therefore affect is_associated_with::male fertility.

Use as a biochemical marker for bone formation
As osteocalcin is produced by osteoblasts, it is often used as a marker for the bone formation process. It has been observed that higher serum-osteocalcin levels are relatively well correlated with increases in bone mineral density (BMD) during treatment with anabolic bone formation drugs for osteoporosis, such as is_associated_with::Teriparatide. In many studies, osteocalcin is used as a preliminary biomarker on the effectiveness of a given drug on bone formation. For instance, one study which aimed to study the effectiveness of a glycoprotein called is_associated_with::lactoferrin on bone formation used osteocalcin as a measure of osteoblast activity.