Afferent arteriole

Efferent arteriole

Filtrate is forced through holes in glomerular capillary walls

Glomerular FiltrationGlomerular FiltrationGlomerular FiltrationGlomerular Filtration

Glomerular capillary:Internal endothelial cell sieve; external covering of podocytes

Varying resistance to flow controls filtration pressure

A-II A-II

Afferent arteriole

Efferent arteriole

A-II vasoconstrictspredominantly the efferent arteriole

Vasoconstriction increases glomerular pressure and filtration

A-II A-IIEfferent arteriole

Afferent arteriole

ACEI and ARBs remove A-II effect:

efferent arteriole dilates

Glomerular pressure and filtration

decrease a little

ACEI reduces glomerular pressure and filtration of albumin remission of nephrotic syndrome due to diabetic nephropathy

Ramipril 5mg daily

eGFR

A-II A-II

Afferent arteriole

Efferent arteriole

Low blood pressure and vascular disease reduce

pressure and flow into glomerulus

Glomerular pressure and filtration

decrease slowly

A-II A-II

Afferent arteriole

Efferent arteriole

Glomerular pressure and filtration suddenly

decrease a lot

ACEI and ARBs remove A-II effect:

efferent arteriole dilates

-----lisinopril-----

--ramipril--

eGFR

1997-2008: ACEI/ARB reduce pressure and slow decline in GFR. Gradual vascular narrowing2008: Critical drop in GFR - ACEI/ARB stopped. GFR recovers

2009: Increased glomerular pressure causes proteinuria

lisinopril 20mg od

irbesartan 75mg odStop both

Proteinuria +++

K+ = 7.5Urea = 22

eGFRACEI and ARBs can be

good or badfor kidney function