When the kidney deaminates glutamine, what does the body gain and what does it lose?

1. Glutamine can be deaminated by the kidney itself, not only by the liver. 2. The amino group is converted into ammonia and pumped into the lumen of the proximal tubule. 3. In the same step sodium and bicarbonate are moved into the interstitial fluid by a symport mechanism. 4. The ammonia in the lumen picks up a hydrogen ion to form ammonium, a weak acid that leaves in the urine. 5. So the body loses a hydrogen ion and gains a bicarbonate ion. 6. Ammonia and bicarbonate are exchanged in a one to one ratio in this process. 7. Both effects push blood pH up, which is why this counts as another way to buffer and excrete acid. 8. An option in which the body loses bicarbonate would make the process worsen an acid load rather than correct it. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 25 "The Urinary System", section 25.6 Tubular Reabsorption_