6. GFR & IT’S REGULATION
Glomerular filtration rate (GFR) is the
measure that describes the total
amount of filtrate formed by all the
renal corpuscles in both kidneys per
minute.
7. • Glomerular filtration is first step of urine
formation.
• It’s begin with filtration of large amounts of
fluid through glomerular capillaries in to
Bowman’s capsule.
• Glomerular capillaries are impermeable to
proteins, cellular elements including RBC’s
8. • Filtered fluid through glomerular capillaries
called glomerular filtrate.
• Some LMWS ( like calcium, fatty acids ) are not
freely filtered, because of partilally bound to
plasma proteins
9. • Glomerular filtration rate (GFR) is equal to the
Clearance Rate when any solute is freely
filtered and is neither reabsorbed nor
secreted by the kidneys.
11. Estimation of GFR
1) Measurement using inulin/ sinistrin
( most accurate)
2) Measurement with radioactive tracers
(Chromium- 51 and 99 m- T)
3) Creatinine-based approximations of GFR.
( most clinically used)
12. U cr * V
Ccr =
P cr
Example: A person has a plasma creatinine
concentration of 0.01 mg/ml and in 1 hour
produces 60ml of urine with a creatinine
concentration of 1.25 mg/mL.
