The aim of this study is to introduce an experimental model to produce blastema tissue and to prepare samples for distinction studies with Transmission Electron Microscope (TEM). Blastema tissue is a group of undifferentiated cells that are able to divide and differentiate in some parts of the body. New Zealand White male rabbits with body weight of less than 2.5 kg and age of nearly 6 months were used in this study. At first with the help of punching techniques 4.5 mL holes were produced in rabbits` pinnas and then in 4, 5, 6, 7, 11, 21 and 24 days after regeneration the tissues around the punching holes were biopsied, using a grasp with more diameter than the one which the holes had been caused by and then samples were prepared for histological studies with electron and objective microscopes. Qualitative and quantitative investigations of electron micrographs demonstrated that in punching site dedifferentiation of blastema cells was obvious. The number of cells of each type were counted and they were compared with each other. The surface of organelles such as cytoplasm, nucleus, endoplasmic reticulum, golgi sacs, mitochondrions, lysosoms and light and dark vacuoles were also measured and compared and then the related data were studied statistically. According to the results obtained from morphologic (cytological) and quantitative studies (comparison between different cellular organelles), The development of Blastema tissue cells regarding the time of study is obvious, so that the existence of chondroblast cells in chondrogenesis and endothelial cells in angiogenesis in 11 and 24 days after regeneration can be seen. So, considering the importance of understanding the blastema cells ultrastructure in mammals, morphology of their development and the fact that it has not been reported so far, this study is the first step and can be continued by other researchers.

Keywords