Glomerular basement membrane

Glomerular basement membrane

Glomerulus; note "Glomerular basement membrane and podocytes".

Scheme of filtration barrier (blood-urine) in the kidney. A. The endothelial cells of the glomerulus; 1. pore (fenestra).
B. Glomerular basement membrane: 1. lamina rara interna 2. lamina densa 3. lamina rara externa
C. Podocytes: 1. enzymatic and structural protein 2. filtration slit 3. diaphragm
MeSH glomerular+basement+membrane

Anatomical terminology

The glomerular basement membrane (GBM) of the kidney is the basal lamina layer of the glomerulus. The glomerular capillary endothelial cells, the GBM and the filtration slits between the podocytes perform the filtration function of the glomerulus, separating the blood in the capillaries from the filtrate that forms in Bowman's capsule.[1] The GBM is a fusion of the endothelial cell and podocyte basal laminas.[2]


The GBM contains three layers: [3]

Layer Location Composition Function
lamina rara externa adjacent to podocyte processes heparan sulfate blocks by charge
lamina densa dark central zone type 4 collagen and laminin blocks by size (Molecular Weight > 5800kDa)
lamina rara interna adjacent to endothelial cells heparan sulfate blocks by charge

The glomerular membrane consists of mesangial cells, modified pericytes that in other parts of the body separate capillaries from each other. The podocytes adjoining them have filtration slits of diameter 25 nm that are formed by the pseudopodia arising from them. The filtration slits are covered by a diaphragm that includes the transmembrane protein nephrin.


Micrograph showing GBM spike formation in membranous nephropathy. Jones stain.

See also

Additional images


  1. Jarad, G.; Miner, J. H. (2009). "Update on the glomerular filtration barrier". Current opinion in nephrology and hypertension. 18 (3): 226–232. doi:10.1097/mnh.0b013e3283296044. PMC 2895306Freely accessible. PMID 19374010.
  2. Physiology: 7/7ch04/7ch04p07 - Essentials of Human Physiology - "Basement Membrane"
  3. JCI - New articles published

External links

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