Effect Of Removal Of One Side Of Condylar To The Opposite Side On Cell Proliferation And Cell Apoptosis

[Objective] To investigate the effect of the removal of one side of the condylar to the opposite side on cell proliferation and cell apoptosis.[Method] Thirty-six 5～6 months old Japanese big-ear rabbits were randomly divided into 3 groups:the blank control group,the sham-operated group and the operation group.The opetation group was created by removing the right condylar. The sham-operated group was create by the same way except not dissecting one side of their condylars. The left condylar (the nonoperative side) cartilages of every group were dissected in 2 months,4 months after the operation accordingly. HE staining was used to observe the histologic changes of the condylar cartilage;Immunohistochemical staining was used to qualitively examine the PCNA positive cell;TUNEL was chosen to detect the apoptotic cell.[Result] HE staining showed that,among the 3 group,from 2 months after the operation to 4 months after the operation, bone trabecula of subchondral bone was thickening;marrow cavity was broadening.At the same time-points,there is no difference beween blank control group and sham-operated group in HE staining;But compared with the blank control group and sham-operated group at the same time-points, among the operation groups, cells were arranged disorder; bone trabecula of subchondral bone was thinning; and these changes of 4 months after the operation was more significant than those of 2 months after the operation. Immunohistochemical staining and TUNEL showed that,compared with the blank control group and sham-operated group at the same time-points,the number of the PCNA positive cells decreased significantly in both 2 months and 4 months operation group; while the number of TUNEL positive cells increased significantly in both 2 months and 4 months operate group(P< 0.05). Compared with the operation group in 2 months after the operation, the number of the PCNA positive cells decreased significantly in the operation group in 4 months after the operation;while the number of TUNEL positive cells increased significantly (P<0.05)[Conclusion] Unilateral condylectomy will decrese the proliferation capacity and increase apoptosis of the opposite condylar,and these effects aggravated as time went on.