Embryo-Histiogenesis of Vascular Tufts of Glomeruli,Possible hypothesis

Embryogenesis of the kidney glomeruli, especially its vascularcomponenthas not beenwell documented.Glomeruli capillary tuftsurroundedand enveloped by and visceral epithelial cellsis a unique portal system that connects afferent with efferent arteriole without interaction with venular circulation. We hypothesized that the portal system embryologically has developed by extension of the intima of afferent arteriole into the stroma of glomerulus. We hypothesize thatJuxtaglomeruli apparatus was developed from remnants of smooth muscle cells of the media of afferent arteriole at the anastomosing site with Bowman capsuleentrance(Dabiri- Moeini hypothesis).In H&E staining of fetal kidney we found presence of RBC in early vesicle form of glomeruli that was confirmed by IHC staining with CD31,SMA,CD34 markers. These stainsshowed that extension of extra-glomerular arterioles to the glomeruli. PAS staining showed also the continuity of the basement membrane in extraglomeruli and internal glomerular vascular tufts. .

Keywords:

Embryology , Kidney , Glomeruli , Vascular tuft