The kidneys produce fewer bicarbonate-ions if the pH of extracellular fluid (ECF), decreases. Normally, the kidneys can maintain the pH level within a narrow range. However, when the kidneys cannot perform their function properly, the pH level in the extracellular fluid can go as high as 8.5. Here are some of the symptoms and treatment options for this condition.
An excess H+ concentration in the extracellular fluid results in acidosis (low pH). Acidosis is a general renal response that involves the resorption and direct secretion (or generation) of hydrogen ions. As the pH of the extracellular fluid increases, the kidneys begin to secrete ammonium and hydrogen ions. This acidifying effect can be countered by the production of new bicarbonate and the resorption filtered bicarbonate.
If the pH level of the extracellular fluid drops, the kidneys begin to produce more bicarbonate and sodium ions. These ions compete with sodium ions in the renal tubules and are exchanged for H+. This conserves bicarbonate, while reducing the volume of sodium in the filtrate. This results in higher bicarbonate absorption by the kidneys due to the loss of chloride.
Another common problem is when the pH of extracellular fluid drops. This condition is called respiratory alkalosis. The kidneys try to compensate for a decrease in bicarbonate concentration by increasing extracellular fluid (ECF). This increases the amount of carbonic acid in blood, which in turn decreases the pH. This causes blood to fall below a physiological level.
The blood contains a mixture of sodium, bicarbonate, and chloride. The intracellular fluid contains a high amount of magnesium and potassium, and a low concentration of protein. This is a problem because a person with kidney disease has increased concentrations of potassium, sodium, and phosphate in their extracellular fluid. When the pH level of the extracellular fluid drops, the kidneys can no longer properly perform their function.
The pH balance between blood and extracellular fluid maintains a pH of 7.4. The pH balance between the blood and extracellular fluid is controlled by the kidneys. Carbonic acid and water are balanced with bicarbonate ions and hydrogen ions. When the pH level of the extracellular fluid drops, the kidneys produce bicarbonate to maintain the pH range. The pH level of the extracellular fluid can be normal or slightly elevated.