Table 1.
Luminal and peritubular composition
|
Luminal Fluid |
Peritubular Interstitium
|
|||||
|---|---|---|---|---|---|---|
| Concentration, mM | Delivered Load,a μmol/min | % Filtrateb | Cortex, mM | OIMJ,c mM | Papillary Tip, mM | |
| Na+ | 65.0 | 14.04 | 9.0 | 144.0 | 284.0 | 284.0 |
| K+ | 2.0 | 0.43 | 8.0 | 5.0 | 10.0 | 20.0 |
| Cl− | 56.1 | 12.12 | 9.4 | 119.6 | 266.0 | 280.9 |
| HCO3− | 8.0 | 1.73 | 6.4 | 25.0 | 25.0 | 25.0 |
| H2CO3, μM | 4.4 | 4.4 | 4.4 | 4.4 | ||
| CO2 | 1.5 | 1.5 | 1.5 | 1.5 | ||
| HPO42− | 2.1 | 2.0 | 3.0 | 3.0 | ||
| H2PO4− | 1.9 | 0.6 | 0.9 | 0.9 | ||
| Total PO4 | 4.0 | 0.86 | 30.8 | 2.6 | 3.9 | 3.9 |
| Urea | 30.0 | 6.48 | 120.0 | 5.0 | 20.0 | 500.0 |
| NH3, μM | 15.1 | 2.9 | 58.0 | 131.4 | ||
| NH4+ | 3.2 | 0.69 | 320.0 | 0.2 | 3.9 | 8.8 |
| pH | 6.828 | 7.323 | 7.323 | 7.323 | ||
| Imp | 0.0 | 2.0 | 2.0 | 2.0 | ||
| Osm | 169.8 | 304.9 | 616 | 1126 | ||
a
Assumes distal flow = 6 nl·min−1·tubule−1 = 216 μl/min for distal convoluted tubule (DCT).
b
Assumes cortical blood concentrations and glomerular filtration rate = 30 nl/min = 1,080 μl/min for DCT.
c
Outer-inner medullary junction.