Sodium-dependent and sodium-independent glutamine transport in the control of ammoniagenesis in rat kidney

Our experiments show Na⁺-dependent and Na⁺-independent uptake of glutamine by renal cortical slices. In a Na⁺-free buffer, sodium azide stimulates glutamine uptake and ammoniagenesis in slices from normal rats but has no effect on slices from acidotic rats. In Na⁺-free buffers azide does not alter ammoniagenesis or glutamine uptake by slices from normal rats but decrease both in slices from acidotic rats. Azide decreases ammoniagenesis in mitochondria from normal rats but increases it in mitochondria from acidotic rats. We conclude that azide stimulates Na⁺-dependent glutamine uptake and Na⁺-independent uptake may be stimulated by acidosis.