Chemical characterization and varying level of the proteoglycans

Proteoglycans are a major component of the animal extracellular matrix, the “filler” substance existing between cells in an organism. Here they form large complexes, both to other proteoglycans, to hyaluronan and to fibrous matrix proteins (such as collagen). Proteoglycans are heavily glycosylated glycoproteins. In this study, we evaluate effect of collagen and proteoglycan on osteoporosis. Rats were treated with ovariectomy (OVX) for 4 weeks to induce osteoporosis. In OVX rats, the levels of collagen and proteoglycan in knee joint cartilage and anterior cruciate ligament were significantly decreased in the OVX group animals compared to the sham group. OVX rats showed decreased levels of magnesium (Mg2+) and calcium (Ca2+), increased concentrations of alkaline phosphatase (ALP) and phosphorus (P) in the serum. We conclude that osteoporosis is closely associated to decreased collagen and proteoglycan levels in knee joint cartilage and anterior cruciate ligament.