Micropuncture studies of the distal nephron and measurements of Na, K-ATPase activity in
microdissected collecting tubules have suggested that renal retention of sodium in
puromycin aminonucleoside (PAN) nephrotic rats originates in the collecting duct. The
present study demonstrated this hypothesis by in vitro microperfusion and showed that
amiloride was able to restore sodium balance. Indeed, isolated perfused cortical collecting
ducts from PAN-treated rats exhibited an abnormally high transepithelial sodium …