科研之友
微信
新浪微博
Facebook
分享链接
摘要
After careful observation of immuno-electron microscopic findings of the renal glomerular podocyte slit so far published by various authors, it should be noted that no convincing evidence is present for localization of nephrin-immunoreactivity in the slit itself, but that nephrin-immunoreactivity is dominantly localized along the membranes of podocyte pedicles from their tip over a substantial extension. In addition, the notion that the slit diaphragm is composed of strands is compatible with the widely distributed view that the slit strands represent rod-shaped nephrin molecules. However, 3-D findings that the diaphragm is composed of not only strands but also membranous elements have recently demonstrated separately by embedment-free section electron microscopy as well as by frozen/deep-etched replica electron microscopy. It is therefore suggested that the molecular composition of the slit diaphragm remain to be further elucidated, and that it is also necessary to re-consider how nephrin is involved in the renal glomerular filtration based on the exact localization along the podocyte membrane, but not in the slit itself. The present author would welcome any criticism and opinion on his consideration. Despu谷s de una cuidadosa observaci車n de los hallazgos inmunoqu赤micos, v赤a microscopio electr車nico, de la hendidura del podocito glomerular renal ampliamente publicados por varios autores, se debe hacer notar que no existe evidencia convincente de la presencia de inmunorreactividad de nefrina en la hendidura propiamente tal, ya que la inmunorrectividad de nefrina est芍 predominantemente localizada a lo largo de la membrana de los podocitos desde su extremo sobre una sustancial extensi車n. Agregado a ello, la idea de que el diafragma de la hendidura est芍 compuesto de filamentos es compatible con la visi車n que los filamentos diafragm芍ticos representan mol谷culas de nefrina en forma de varilla. Sin embargo, hallazgos en 3D muestran que el diafragma est芍 compuesto no solamente de filamentos sino que tambi谷n por elementos membranosos que han sido demostrados recientemente por secci車n libre de microscop赤a electr車nica (embedment-free), as赤 como tambi谷n por microscop赤a electr車nica de r谷plica por congelaci車n y grabado profundo (frozen/deep-etched). Por lo tanto, se ha sugerido que la composici車n molecular del diafragma de filtraci車n permanece para ser estudiada en el futuro y que es tambi谷n necesario reconsiderar como la nefrina est芍 involucrada en la filtraci車n glomerular renal basados en la localizaci車n exacta a lo largo de la membrana del podocito pero no en la hen
