Final answer:
Renal tubular acidosis is characterized by deficient H+ secretion in renal tubules, causing metabolic acidosis, which can facilitate the formation of calcium phosphate kidney stones by increasing urine pH and promoting crystal precipitation.
Step-by-step explanation:
The association between renal tubular acidosis (RTA) and abnormal H+ secretion is that in RTA, there is a defect in the renal tubules that impairs acid secretion. This can lead to an acidic environment within the body, called metabolic acidosis. RTA can also contribute to the development of nephrolithiasis, commonly known as kidney stones. In particular, the formation of calcium phosphate stones can be associated with RTA.
When H+ secretion is impaired, there is less acidic urine and consequently, a less favorable environment for uric acid to dissolve. Furthermore, a high pH in the urine can promote the precipitation of calcium phosphate crystals, leading to stone formation. This condition may exacerbate if there is also excess bicarbonate in the blood, as bicarbonate can increase urinary pH. Additionally, the secretion of ions, which is responsible for creating osmotic pressure in the urine, can affect water, electrolytes, and uric acid, further contributing to stone formation. Therefore, proper acid-base balance maintained by the kidney is crucial in preventing nephrolithiasis.