2.  Glucose is reabsorbed completely from
PCT
 Its reabsorbed along with sodium
 Na+ is pumped out of Tubular cells by
Na-K Atpase pump in the basal side
 This decreases intracellular Na
concentration

3.  Uses Sodium glucose co transport (SGLT)
 Thus glucose absorption from lumen is
secondary to active transport on the
basal side
 Secondary active transport

4.  SGLT 1& 2
 Similar to the one present in the intestine
 It transport glucose and sodium along
with various solutes like amino acids .
Lactate and phosphates
 From the tubular cells glucose reaches
interstitium by GLUT-2

5. 5

6.  Membrane channels which helps in
transporting glucose into to cell
 Induced by insulin
 Facilitated transport
 Totally 7 GLUT are found

7.  For most subs that are actively secreted
or reabsorbed there is a limit to rate at
which solute can be transported
 carrier system gets saturated if the
tubular load is more than transport
maximum
 Tm refers to tubular load at which the
carriers gets saturated
 Normal TmG for males is 375mg/min
 For females – 300mg/min

8.  Tubular load is the amount of glucose filtered
by the glomerulus
 Tubular load of 375mg/min correspond to
300mg/dl of plasma concentration
 filtered load of glucose (GFR x Pglu); units:
mg/min
 Filtered load of glucose = GFR x plasma [glucose]
 Tubular load = 125ml/min*300 mg/dl
= 125ml/min*3mg/ml
= 375mg/min

9.  Plasma concentration above which the
glucose first appears in urine
 Normal 200mg/dl in arterial blood
 180 mg/dl in venous blood

10. 10

11.  Region of glucose curve between
threshold and TmG
 Represent the excretion of glucose in the
urine before TmG is reached

12.  Not all nephrons have same Tm for
glucose
 Overall Tm is 375 but it’s the average
 variability in nephron size

13.  Increased load of solute to tubules will
produce more urine because of osmotic
diuresis
 Ex – diabetes mellitus

14. ↑plasma glucose

↑filtered glucose

Tm exceeded

glucose remains in tubules

H2O retained osmotically

increased urine volume

if not replaced by drinking, blood volume decreases
Increased urine volume in diabetes mellitus

15.  Normally a small amount of protein is
filtered by glomerulus and almost all of it
absorbed by PCT
 150mg/day is excreted in urine normally
 Constitutes 15mg of Ab and rest LMWP
and 25mg of which is Tamm horsfall
protein

16.  Glomerluar proteinuria
 Tubular proteinuria
 Overflow proteinuria
 Nephrogenic proteinuria