Glomerular basement membrane
The glomerular basement membrane is the basal laminal portion of the glomerulus which performs the actual filtration though the filtration slits between the podocytes , separating the blood on the inside from the filtrate on the outside. It is a fusion of the endothelial cell and podocyte basal laminas. [1]
Layers
The GBM contains three layers: [2]
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 (MW > 69,000) |
lamina rara interna | adjacent to endothelial cells | heparan sulfate | blocks by charge |
Pathology
- Goodpasture's syndrome is also known as "anti-glomerular basement membrane disease". Capillaries become inflamed as a result of damage to the basement membrane by antibodies.
- Nephrotic syndrome is a change in the structure of the glomerular filtration mechanism usually in the glomerular basement membrane. Some symptoms include proteinuria, hypoalbuminaemia, oedema, and hyperlipidemia.
- Diabetic glomerulosclerosis is a thickening of the basement membrane, which can become up to 4-5 times thicker than normal. Can be caused by insulin deficiency or resultant hyperglycemia.
See also
References
- ↑ Essentials of Human Physiology by Thomas M. Nosek. Section 7/7ch04/7ch04p07. - "Basement Membrane"
- ↑ http://www.jci.org/cgi/content/full/116/8/2090/F1
External links
- glomerular+basement+membrane at the US National Library of Medicine Medical Subject Headings (MeSH)
- "The GBM and its disorders" at dmed.ed.ac.uk
- Histology at harvard.edu
- Structure at wramc.army.mi