The interaction between gluconeogenic metabolism and accumulation of phosphate by chick kidney tubule cells.

Pyruvate promotes both phosphate uptake and glucose synthesis by isolated chick kidney proximal tubule cells. 3-Mercaptopicolinate inhibits both glucose synthesis and the promoted phosphate accumulation to the same extent. Glycerol also stimulates glucose synthesis, but does not affect phosphate accumulation. Oxygen utilization by the tissue is slightly stimulated by glycerol and pyruvate, but the enhancement of uptake by pyruvate is unlikely to result from raised cellular oxidative phosphorylation. The action of pyruvate is not a direct effect on the phosphate transporter, or on the transport of phosphate across the basolateral membrane, but entails an obligatory flux to triose phosphate.