Quantitative Analysis Of Osteogenesis After Tensile Force Application To The Interparietal Suture Of Sprague-dawley Rat

Purpose:Measurement of BMP immunohistochemically stained in suture tissue of the in vivo interparietal suture expansion model was performed by microscope image analysis system, calculate the number of osteoblasts cytochemically stained about AKP, and with the routine H.E.staining, to quantitatively analyze osteogenesis of the suture after expansion.Methods:72 Sprague-Dawley rats were divided into a baseline group, a control group and an experimental group at: random, and were sacrificed 4,7 and 14 days after application of the tensile force. The suture sections were stained with endogenous bone morphogenetic proteins using immunohistochemical SP method and were stained with alkaline phosphatase using cytochemical method. The parameters of bone-suture length, suture area, BMP area integrated optical density(AIOD) and BMP averaged optical density (AOD) were valued by TIGER image analyzer to evaluate the changes of BMP level. The number of positive stained osteoblasts was counted to calculate the percent of positive cell along the edge of suture. The tissue sections were stained with routine H.E. method to observe the general morphological changes.Results:(DThe suture area in the experimental group increased significantly at the timepoints of 4th day and 7th day under 100g tensile force.(2)The level of bone-suture length, BMP area integrated optical density(AIOD) andBMP averaged optical density (AOD), and the percent of active stainedosteoblasts in the experimental group reached the highest at the time point of 7thday.(3)The suture area was similar at the two time points of 4th day and 7th day in theexperimental group.Conclusions:(l)The connective tissue of the interparietal suture appeared in the state ofcontinuously overwhelming fibrogenesis until 7 days of 100g tensile forceapplication.(2)The activity of osteogenesis reached the highest at the time point of 7th day.(3)The bone matrix formation and mineralization remained active at the time pointof 14th day.(4)It was feasible to measure BMP level by microphotometry.