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HugoBossPT OP t1_j3h0bm6 wrote

Reply to comment by uh-okay-I-guess in How does the renal HCO3- reabsorption increase blood pH? by HugoBossPT

That makes sense. So some ventilation problem that would cause CO2 levels to rise would shift the equilibrium to the H+ (and HCO3-) side, lowering pH. To compensate, the body would reabsorb as much HCO3- as possible to "reshift" the equilibrium to the original state. Am I thinking right? Thank you!!

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uh-okay-I-guess t1_j3k2c1m wrote

Yes, the kidney will retain bicarbonate, but unfortunately, under normal conditions the kidney already reabsorbs close to 100% of bicarbonate. So unfortunately this mechanism cannot be increased enough to fully compensate for respiratory acidosis.

The kidney has other methods to indirectly raise the pH, like excreting ammonium (which would otherwise be reacted with bicarbonate in the liver). Other acids can also be excreted. However, renal compensation for respiratory acidosis takes days. The lungs are much faster at removing acid from the body than the kidney is.

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