The effect of gluconeogenesis on phospholipid turnover in isolated chick proximal tubule cells.
Previous work from this laboratory has shown that isolated chick renal proximal tubule cells possess an Na+-dependent Pi transport system and that Pi uptake is stimulated under gluconeogenic conditions. It is shown in the present paper that gluconeogenesis is associated with a rapid incorporation of Pi into membrane phospholipids, particularly phosphatidylinositol, and some evidence has been obtained for a change in the relative amounts of phosphatidylinositol polyphosphates under gluconeogenic conditions. There is no increase in the total phospholipid phosphate content however, suggesting that pyruvate-induced incorporation of Pi into phospholipids represents accelerated turnover rather than a net increase in synthesis. It is suggested that the stimulation of Na+-dependent Pi uptake by pyruvate is related to the increased rate of phospholipid turnover. Thus Pi transport may be a further example of a physiological system that is influenced by phosphatidylinositol metabolism. The role of phosphatidylinositol phosphates could be to stimulate transfer of transporter molecules from internal stores to the brush-border membrane of the cell.
D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000818:Animals; D002645:Chickens; D005943:Gluconeogenesis; D066298:In Vitro Techniques; D007687:Kidney Tubules, Proximal / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D011773:Pyruvates / Q000494:pharmacology; D019289:Pyruvic Acid
D010710:Phosphates; D010743:Phospholipids; D010761:Phosphorus Radioisotopes; D011773:Pyruvates; D019289:Pyruvic Acid; D000255:Adenosine Triphosphate