en Microbiology and Anatomy Microbiology and Anatomy Original Research: Basic Science in Medicine Original Research: Basic Science in Medicine Glomerular development of the kidney was studied in newborn rats by electron microscopy. Four different stages of glomerular development were defined: vesicle fonnation, S-shaped body stage, capillary loop fonnation, and glomerular maturation. In the fust stage, the mesenchymal cells form a spheroid mass. This is followed by the S-shaped body stage in which clefts appear in the mass. Afterwards, capillary loop formation, junctional migration, podocyte differentiation, and interdigitation of epithelial processes occur. Finally, the cytoplasm of endothelial cells becomes thinner. The urinary space is visible in this stage. The fusion of epithelial and endothelial basement membranes results in fonnation of the layers of the GBM. The increase in the number of podocyte processes and endothelial cell fenestrations are important events in the maturation phase. Development, Glomerular stages, Basement membrane 147 152 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-545&slc_lang=en&sid=1 M NOBAKHT 20031947532846005930 20031947532846005930 Yes From the Department of Anatomy, Tarbiat Modarres University, and the Cancer Institute of Imam Khomeini Hospital, Tehran, Islamic Republic of Iran. MT TAKl 20031947532846005931 20031947532846005931 No M REZAZADEH 20031947532846005932 20031947532846005932 No S SHARlAT TORBAGHAN 20031947532846005933 20031947532846005933 No