Bicarbonate handling in kidney
- Freely filtered at glomerulus
- 80% HCO3 reabsorbed at proximal tubule
- transported into interstitium by Na/HCO3 symporter
- 10-15% reabsorbed at thick ascending limb of Loop of Henle
correcting alkalosis
- ↓ pCO2 = ↓ secretion of H+
- Bicarb that cannot react with H+ is not reabsorbed and excreted in urine