Concurrent measurement of Gla-osteocalcin and Glu-osteocalcin may be achieved with the Pig Gla-Osteocalcin EIA Kit (Cat. #MK139) and Pig Glu-Osteocalcin EIA Kit (Cat. #MK149) to monitor both bone formation and bone resorption, based on a relative evaluation of Gla/Glu-osteocalcins.
Osteocalcin (OC) comprises 49 amino acids, including 2 to 3 γ-carboxyglutamate residues (Gla), and has a molecular weight of approximately 5,900. It is known as a vitamin K-dependent calcium-binding non-collagen protein. Osteocalcin is an osteoblast-specific marker as it is produced only by osteoblasts. It is also a hormone that plays an important role in glucose metabolism. While carboxylated osteocalcin (cOC) is the active form of the protein in bone metabolism, undercarboxylated osteocalcin (ucOC) is the active form of the protein in glucose metabolism.
Animal Model for Bone Remodeling
In bone formation, the dynamic osteogenesis in growing young animals is called "modeling" (new construction). In matured animals beyond the growing phase, bone morphology undergoes no apparent changes and remains stable, but a certain percentage of the bone are constantly being replaced. This process is called "remodeling" (reconstruction). Efficacy assessments of osteoporosis drugs require the use of 2 types of animal models to allow evaluation for bone modeling and remodeling. Rodents, such as mouse and rat, are commonly used animal models to evaluate modeling, while monkey and miniature pig are used frequently to evaluate remodeling. These animal models are essential in the developments and efficacy assessments of potential therapeutic agents.
Quantitative Osteocalcin Analysis
The Pig Gla-Osteocalcin EIA Kit (Cat. #MK139) is a quantitative kit that enables specific and highly sensitive assay of porcine Gla-osteocalcin that exhibits a potential to osseointegration (active osteocalcin). The capture antibody is a plate-bound solid-phased monoclonal antibody that specifically recognizes the Gla residue at position 17 on osteocalcin. It is paired with a labeled monoclonal antibody for detecting porcine osteocalcin.
The Pig Glu-Osteocalcin EIA Kit (Cat. #MK149) is a quantitative kit that enables specific and highly sensitive assay of decarboxylated osteocalcin released from porcine bone tissues by enzymes in osteoclasts or undercarboxylated Glu-osteocalcin (ucOC; inactive osteocalcin) produced by osteoblasts. The capture antibody is a plate-bound solid-phased monoclonal antibody that specifically recognizes the Glu residues at positions 21 and 24 on osteocalcin. It is paired with a labeled monoclonal antibody for detecting porcine osteocalcin.
