The influence of osteoclasts during the repairs of tooth root in rats model of tooth resorption by intermittent injection of parathyroid hormone (PTH) / 重庆医学

ABSTRACT

Objective To investigate the role of PT H (1-34 ) on the expression of receptor activator factor of NF-κB ligand (RANKL) in the induction of osteoclasts and its effect to osteoclasts on compression side during the repairs of tooth root in rats model of tooth resorption by intermittent injection of small dose of PTH (1-34) .Methods After the model of tooth resorption was established in rats 6-8 weeks in age ,63 male SD rats were divided in three groups .Rats in the control group were not given injec-tions for any drugs ;The negative control group were given injections for normal saline 6μg/kg subcutaneously every other day ;The experimental group were given injections for PTH (1-34) 6 μg/kg(PTH1 μg/mL) subcutaneously every other day ;then rats in every group were killed on the day 0 ,7 ,10 ,14 ,17 ,21 ,25 .TRAP staining for counting TRAP-positive stained osteoclasts ,calculat-ing the mean ;Ligand RANKL immunohistochemistry and using image-pro-plus image analysis system to measure the average opti-cal density value of compression side .Results On the day of discontinuation ,the tooth resorption continued in each group ;the num-ber of osteoclasts between every two arrays there were no significant statistic differences (P>0 .05);RANKL immunohistochemis-tryCompared with control group and the negative control group ,the experimental group significantly increased in early stage ,and reduced in latest stage(P<0 .05) .Conclusion It indicated that intermittent injection of small dose PTH (1-34) did not cease the rats tooth resorption which occured during the period of tooth repair .