A molecular view of proximal tubular inorganic phosphate (Pi) reabsorption and of its regulation
H Murer, J Biber - Pflügers Archiv, 1997 - Springer
H Murer, J Biber
Pflügers Archiv, 1997•SpringerIn recent years, two mammalian proximal tubular brush border membrane Na/P i
cotransporters (types I and II) have been structurally identified by expression cloning
techniques. Oocyte expression studies have shown that only the transport characteristics of
the type II transporter correspond to the well-known properties of proximal tubular brush
border membrane of P i transport. In studies on physiological regulation by hormonal and
non-hormonal factors a direct involvement and determining role of the type II transporter has …
cotransporters (types I and II) have been structurally identified by expression cloning
techniques. Oocyte expression studies have shown that only the transport characteristics of
the type II transporter correspond to the well-known properties of proximal tubular brush
border membrane of P i transport. In studies on physiological regulation by hormonal and
non-hormonal factors a direct involvement and determining role of the type II transporter has …
Abstract
In recent years, two mammalian proximal tubular brush border membrane Na/Pi cotransporters (types I and II) have been structurally identified by expression cloning techniques. Oocyte expression studies have shown that only the transport characteristics of the type II transporter correspond to the well-known properties of proximal tubular brush border membrane of Pi transport. In studies on physiological regulation by hormonal and non-hormonal factors a direct involvement and determining role of the type II transporter has been documented. Most interestingly, specific membrane retrieval/insertion phenomena participate in acute (minutes/hours) adjustments of brush border membrane Na/Pi cotransport rates; for chronic (hours/days) alterations also specific resynthesis/degradation processes participate. In pathophysiological alterations (e.g. in X-linked hypophosphataemia and in heavy metal-induced nephrotoxicity) the expression of the type II Na/Pi cotransporters is reduced and explains the observed phosphaturia.
Springer
