 This urinary acidity is, to a certain extent, neutralized by the ammonia (NH3) which is excreted into the urine when glutamate and glutamine (carriers of excess, no longer needed, amino groups) are deaminated by the distal renal tubular epithelial cells.Thus some of the "acid content" of the urine resides in the resulting ammonium ion (NH4+) content of the urine, though this has no effect on pH homeostasis of the extracellular fluids.Acid–base imbalance occurs when a significant insult causes the blood pH to shift out of the normal range (7.32 to 7.42).