Hello,

The kidney's main role in acid-base homeostasis is:

1. To reabsorb filtered bicarbonate
2. To excrete daily net acid (H+) load.

The first item helps prevent loss of bicarbonate in to the urine once it is filtered by the glomerulus. The second item helps regenerate bicarbonate that was consumed during the buffering of exogenous acids.

Dr. Jordan Weinstein