بررسي تغييرات غشاء پايه ، آنزيمهاي ليزوزوفي و مرگ سلولي در تكوين زوايد كامي جنين موش بزرگ صحرايي

Survey of the Changes in Basement Membrane, Lysosomal Enzyme and Cell Death in Rat Palatal Shelves Development

Objective: Development of secondary palate in the fetues rat occurs in five stages. Initially, the palatal shelves grow vertically down the side of the tongue, then to a horizontal position above the dorsum of the tongue. This event occurs simultanous or non-simultanous to the next stage, palatal shelves near each other to the midline palatal seam. Finally, the midline epithelial seam is fragmentated and lost. The aim of this study was to survey the changes in basement membrane, acid phosphatase and cell death in animal model palatal shelves development. On the 16th day of gestation in rats, palatal shelves are fused. Material and Methods: In order to study the development process of palate, 30 embryos were used on the 16 day at the interval of the two hours. Some of the cases were frozen in a solution of nitrogen and maintained at a temperature on 20°C in the refrigerator. The frozen serial section were prepared with 5 and 10 gm thickness with cryostat. The other cases were fixed in solution of normal saline and aceton. Samples were prepared for histological study and were stained by hematoxylin & eosin, P.A.S and diastase, feulgen, periodic acid-silver nitrate and acid phosphatase. Results: The results of histologic study indicated the basal membrane during and prior to contact disrupt (Specially in the anterior portion) and the region of midline seam disappear. Macrophages in the development of palate oocurs prior to fuse in portion anterior, midline seam and islands of epithelial. Active of Acid phosphatase indistinct in the middle epithelial seam that is occurs in the triangle of superior and inferior. The results of histologic study occurred in the medial edge epithelium seam proccss of cell death. Conclusion: The results of this study show that cell death have important roles in palatal, embryo development.