- Joined
- Feb 13, 2003
- Messages
- 538
- Reaction score
- 1
I'm trying to understand why both calcium and phosphate excretion increase in acidosis. I think this is why, but didn't specifically read this anywhere-- can someone help me out??
1. acidosis leads to increase free C++ by displacing it from albumin (90% of C++ in serum is bound to albumin)
2. that causes an increase of calcium in the blood
3. PTH levels decrease in response to increased Ca++
here's where it gets tricky:
4. a lower PTH will cause an increase in Ca++ excretion, but a DECREASE in phosphate excretion
5. at the same time, phosphate ion is used to bind H+ for excretion of H+(and simultaneous absorption of a new HCO3-) during correction of acidosis.
6. #5 is a stronger effect than #4.
Is this still valid then for a renal tubular acidosis?
1. acidosis leads to increase free C++ by displacing it from albumin (90% of C++ in serum is bound to albumin)
2. that causes an increase of calcium in the blood
3. PTH levels decrease in response to increased Ca++
here's where it gets tricky:
4. a lower PTH will cause an increase in Ca++ excretion, but a DECREASE in phosphate excretion
5. at the same time, phosphate ion is used to bind H+ for excretion of H+(and simultaneous absorption of a new HCO3-) during correction of acidosis.
6. #5 is a stronger effect than #4.
Is this still valid then for a renal tubular acidosis?
