Table 4.

Parameter values identified using experimental data on sodium and urea kidney concentrations, fluid reabsorption, urine flow, and sodium as well as urea urine concentration for a normal hydration state.

Parameter	Identified value
WATER CONDUCTIVITY [L2/(min μmol)]
R (i  Proximal tubule)	1.2E−7
R (i  Descending Henle’s loop in outer Medulla)	2.7E−11
R (i  Descending Henle’s loop in inner Medulla I)	2.35E−10
R (i  Descending Henle’s loop in inner Medulla II)	1.0E−12
R (i  Distal tubule)	6.77E−8
R (i  Collecting duct in cortex)	7.406E−9
R (i  Collecting duct in outer medulla)	5.078E−9
R (i  Collecting duct in inner medulla I)	1.164E−9
R (i  Collecting duct in inner medulla II)	4.443E−11
RATE CONSTANTS SODIUM TRANSPORT (L/min)
kactive (i  Proximal tubule)	2.48E−4
kactive (i  Ascending Henle’s loop in outer medulla)	7.87E−4
kactive (i  Distal tubule)	5.11E−4
RATE CONSTANTS SODIUM DIFFUSION (L/min)
kpassive (i  Ascending Henle’s loop in inner medulla II)	2.5E−3
kpassive (i  Ascending Henle’s loop in inner medulla I)	2.5E−3
RATE CONSTANTS UREA DIFFUSION (L/min)
kpassive (i  Proximal tubule)	8.2E−9
kpassive (i  Ascending Henle’s loop in inner medulla II)	4.89E−6
kpassive (i  Collecting duct in inner medulla I)	1.39E−6
kpassive (i  Collecting duct in inner medulla II)	4.45E−5
SURFACE AREA DVR (cm2)
S (j  Outer medulla)	1.0E−3
S (j  Inner medulla I)	1.0E−4
S (j  Inner medulla II)	1.0E−4

The values for water conductivities and rate constants refer to the long loop nephrons. The values for short loop nephrons are obtained by scaling the values for the long loop nephrons by the ratio of the number of short loop nephrons to the number of long loop nephrons.