Interrelationships between influx, efflux, and sequestration coefficients for the DM and the GM and their physical equivalents
| Coefficient | Coefficients for DM1-a | Coefficients for GM1-b | Physical Equivalents for GM1-b |
|---|---|---|---|
| sec−1 | ml sec−1 ml−1 | ml sec−1 ml−1 | |
| Influx | k 12 |
|
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| Efflux | k 21 | k′−1 or ftk −1 |
|
| Sequestration | k e | k′seq or ftk seq |
|
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↵1-a Transfer coefficients for the DM.
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↵1-b Transfer coefficients for the GM and their physical equivalents.
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1-c k1 =PinS/Vcell; θ′ = θ/(1 + γref); θ = Vcell/Vp, where Vp is the sinusoidal plasma volume andVcell is the cellular water volume; γref = [fu γSuc + (1 −fu)γAlb] is the apparent space ratio (interstitial/total vascular space) for total substrate;fu is the fraction of unbound tracer within the vascular plasma space; and γAlb and γSuc are the ratios of the interstitial space to the vascular plasma water space for albumin and sucrose, respectively.
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1-d PinS is the influx permeability cell surface area product,PoutS is the efflux permeability cell surface area product, and ft is the unbound fraction in tissue.
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1-e CLint, the hepatic intrinsic clearance for removal, equals Vmax/(Km +Ct,u), where Vmax is the maximum velocity per unit of cell water, Km is the corresponding Michaelis-Menten constant for the irreversible removal of substrate, and Ct,u is the average unbound concentration in tissue water.