GFR Biochem Flashcards
What would an ideal marker of GFR be?
not secreted by or reabsorbed from the renal tubule
freely filtered at the glomerulus
Why does inulin not make a good marker of GRF?
hard to measure - would need to inject the inulin into somebodys body as it is not normally produced by the body
What is the problems of using urea as a marker of GFR?
does not appear at a constant rate - rise significantly in response to protein
is reabsorbed
What is the problem of using creatinine as a marker of GFR?
larger muscle mass means an increased creatinine production
What is used as a marker of GFR?
eGFR
What is eGFR?
takes variables into account: creatinine, urea, age, sex, albumin
What is a normal GFR?
> 120
What happens to creatinine levels when GFR is low?
creatinine rises a lot - very sensitive
What happens to creatinine levels when GFR is high?
creatinine falls a little - not so sensitive
What protein level a day indicates significant glomerular damage?
> 150mg/day
What can overflow of proteins into urine cause?
nephrotic syndrome
What is microalbuminuria?
excretion of albumn in abnormal quantities but still below the level of protein detection by dipstick
What does microalbuminuria indicate?
diabetic nephropathy
How can diabetic nephropathy be slowed down?
ACE inhibitor
How is tubular fuction measured?
comparing urine osmolarity and serum osmolarity
- the more similar the two, the worse - i.e nothing being filtered through
