Research In The Influence Of Collagen Type Ⅱ For The Mandibular Condylar Chondrocytes And The Articular Chondrocytes Of Femoral Head Under Mechanical Force In Rats

[Objective] Base on the mandibular condylar chondrocytes and the femoral articular chondrocytes in vitro. Compare the synthesis of collagen typeâ…¡of the two type of chondrocytes underloading compressure to lasting for some time. To explore the influence defference of the pressure for defferent chondrocytes from their extracelluar matrix components. Using defferent biomechanical characteristics to primary discuss the method of rebuilding the articular cartilage for curing osteoarthrosis and malocclusion.[Method] Using 2-week SD rats to separate and culture the mandibular condylar chondrocytes and femarol articular chondrocytes in vitro by mechanical add enzyme digestion method, they had build their limited cell lines, identified by immunohistochemical of collagen typeâ…¡.Underloading 0.01MPa compressure to the third period chondrocytes, the experiment time are divided into 0.5h, 3h, 12h for the two type chondrocytes. But control groups were not loaded on pressure. Every group had the same conditions except the time of loading compressure. The expression of collagen typeâ…¡was observed by RT-PCR. The statistical analysis was used to comparise the statistical significance between each groups with t test.[Result] under 0.01MPa static pressure lasting 0.5h, the expression of collagen typeâ…¡of both condylar chondrocytes and femarol articular chondrocytes were slightly increased,as that of control group also increased,it has no obvious difference. When the pressure force last 3h, the expression of collagen typeâ…¡of both condylar chondrocytes and femarol articular chondrocytes were obvious increased, and has significant differences to comparise with each control, but no significant differences between the mandibular condylar chondrocytes and femarol articular chondrocytes, as the expression of collagen typeâ…¡in mandibular condylar chondrocytes has a little more than femur. After loading force for 12hours, the expression of collagen typeâ…¡of both condylar chondrocytes and femarol articular chondrocytes were decreased obviously (p<0.05), as the level of collagen typeâ…¡in mcc was lower than femarol articular chondrocytes, but still has no statistically significant.[Conclusion] During a certain period, the synthesis of collagen typeâ…¡could increase with the time prolonging. But if pressure loading time exceed a extent excessively, the synthesis of collagen typeâ…¡may be inhibited and may stimulate its catabolism. Under the same mechanical stress, the trend of the expression of typeâ…¡collagen for both chondrocytes were similar, whereas that of mcc was a little more obviously. This conclusion may suggest that, articular cartilage cell can be regulated by mechanical stimulation, and the secondary cartilage may be more susceptible and sensitive to the compressure than the primary cartilage.