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Minimal Change Disease

2K views 5 replies 4 participants last post by  gokulramani 
#1 ·
Does anyone know the mechanism behind the selectivity of albumin in the proteinuria associated with MCD?
 
#2 ·
Yes -- albumin is the most abundant protein in the blood. In most cases, albumin is the protein in proteinuria. It's also a fairly small protein and can pass through the glomerulus.

Also within the pathophysiology of MCD is the idea that you diminish the negative charge of the GBM. Usually, both albumin and the GBM have a negative charge which helps repel albumin and prevent it from passing, but as the charge is lost it's easier for alb to pass on through and ultimately into the urine.
 
#4 · (Edited)
One more thing that they like to test regarding this concept is the fact that GBM plus ENDOTHELIUM forms the charge barrier to plasma proteins. GBM plus EPITHELIUM podocytes form the SIZE barrier hence limit the particles based on size. It is the charge barrier that is lost in MCD. About diabetes, there is microfiltration due to GBM thickening caused by non enzymatic glycosylation of the GBM.
 
#6 ·
3 Layers . Epithelium (size - 40nm)
Basement membrane (4nm)
Endothelium (Aka podocyte) (4nm with neg charge cuz of HEPARAN SULFATE(a glycosaminoglycan)

Albumin is 3.6nm. And its Negatively charged.

In MCD, podocytes(4nm) get FLATTENED(effaced) and loose the neg charge. Basement membrane(4nm) isnt lost even if podocytes are lost.

Albumin is near to the size of the endothelial gap. Hence selective :rolleyes:
 
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