Glutamine homeostasis: role of pCO2 in regulating arterial glutamine in metabolic acidosis.

In chronic metabolic acidosis arterial plasma glutamine concentration is reduced 46%. This effect is attributable to a reduction in arterial pCO2 rather than acidemia since elevating pCO2 returns glutamine toward the control level. The extracellular glutamine precursors ammonia and glutamate exhibit a reciprocal decline with the elevation in pCO2. This reduction in metabolic acidosis appears to play an important role in sparing glutamine for renal base generation.