Expression Of Parathyroid Hormone-related Peptide In Carltilage Of Immobilization Osteoarthritis And Ovariectomized Rabbits

Objective: TO study the morphology of articular cartilage in estrogen deficiency rabbits and to evaluate the expression of parathyroid hormone-related peptide in cartilage of immobilization osteoarthritis and ovariectomized rabbits. Methods: Twenty-five New Zealand white female rabbits were classified into three groups: right knee immobilization osteoarthritis (group A); ovarietomized (groupB) and normal control animals (group C). All animals were killed 56 days after groupA immobilization, specimens of right knee cartilage were harvested from femoral condyles. The samples were stained with Safranin and fast green, all sections were graded by HHGS. Parathyroid hormone-related peptide was visualized using a streptavidin-horseradish peroxidase enzyme conjugate method and the percent of positive cells were counted. Results: The rabbit knee immobilization model is reliable osteoarthritis model. The Safranin stainings were slight to moderate reduction in ovariectomized rabbits articular cartilage indicated that the proteoglycan concentrations were reduced. Parathyroid hormone-related peptide expression was detected in normal cartilage by immunohistochemistry studies and parathyroid hormone-related peptide was also presented in osteoarthritis and ovariectomized cartilage saniples, but was more widely and intensely expressed. Conclusion: Immobilization models of degenerative osteoarthritis were reliable and suitable for the study of osteoarthritis. Estrogen deficiency plays a improtant role in the pathogenesis of the osteoarthritis. Parathyroid hormone-related peptide was more abundant in osteoarthritis and estrogen deficience rabbits than in normal knee articular cartilage. Our results suggest that parathyroid hormone-related peptide may be involved in the pathophysiology of osteoarthritis, it may act as a protective factor against cartilage destruction.