Huamin Wang, Hubert Zajicek, Vijay Kumar, Paul Wilson, and Moshe Levi

Department of Medicine, The University of Texas Southwestern Medical Center at Dallas and Department of Veterans Affairs Medical Center, Dallas, Texas 75216, USA

Received 1/13/97; Accepted 1/13/97; On-line 02/01/96

1. ABSTRACT

The kidney plays a critical role in the regulation of inorganic phosphate (Pi) homeostasis through changes in the proximal tubular apical membrane Na-dependent Pi (Na/Pi) transport activity. In response to alterations in dietary Pi intake and during the aging process, changes in renal Na/Pi transport activity are inversely correlated with apical membrane cholesterol content. Cholesterol regulates Na/Pi transport activity by fluidity-dependent and fluidity-independent mechanisms, including regulation of Na/Pi protein transcription, synthesis, and trafficking to and from the plasma membrane.