* When H<sup>+</sup> is binding to buffers other than bicarbonate it is excreted. This means that the reabsorption of bicarbonate represents a net gain of bicarbonate not just a replacement of what was filtered. This results in an increase in plasma pH. | * When H<sup>+</sup> is binding to buffers other than bicarbonate it is excreted. This means that the reabsorption of bicarbonate represents a net gain of bicarbonate not just a replacement of what was filtered. This results in an increase in plasma pH. |