Jia Yu, Sakari Laaksonen, Eerika Mursu, Matleena Typpö, Paula Pesonen, Hanna-Marja Voipio, Simo Saarakkala, Aune Raustia, Pertti Pirttiniemi
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引用次数: 1
Abstract
Aims: To investigate how estrogen level, dietary loading, and aging affect cartilage structure and the expression of major collagens (types I, II, and X) in rat mandibular condylar cartilage (MCC).
Methods: A total of 96 outbred Sprague Dawley female rats were randomly divided into two groups by ovariectomy (OVX) at 7 weeks old. One week later, the rats in each group were further divided into three subgroups on the basis of food hardness: hard food (diet board), normal food (pellet), and soft food (powder). The rats were sacrificed at the age of 5 or 14 months. The thickness of the fibrous, proliferative, and chondroblastic layers of the mandibular condylar cartilage were measured after toluidine blue staining. Immunohistochemical analysis was performed to evaluate the expression levels of types I, II, and X collagen. A linear regression model was used to investigate the main factors affecting changes in thickness and collagen expression.
Results: The expression levels of types II and X collagen were decreased by ovarian estrogen deficiency and increased by dietary loading. Increased dietary loading was the main factor affecting an increase in thickness of the cartilage layers, while aging was the main factor affecting a decrease in thickness of the fibrous layer. A significant age-related increase was found in the expression of type I collagen. There was some degree of interaction between aging and dietary loading that affected the thickness of the chondroblastic layer and the expression of type X collagen.
Conclusion: The physiologic level of estrogen plays a role in MCC development by promoting the expression of types II and X collagen. Dietary loading is essential to increase the expression of types II and X collagen, as well as the thickness of cellular layers, to maintain the integrity of the MCC. Aging seems to reduce the ability of the MCC to withstand occlusal loading.
期刊介绍：
Founded upon sound scientific principles, this journal continues to make important contributions that strongly influence the work of dental and medical professionals involved in treating oral and facial pain, including temporomandibular disorders, and headache. In addition to providing timely scientific research and clinical articles, the journal presents diagnostic techniques and treatment therapies for oral and facial pain, headache, mandibular dysfunction, and occlusion and covers pharmacology, physical therapy, surgery, and other pain-management methods.
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