Soluble Receptor Concentration
Soluble receptors can be formed from enzymatic cleavage of membrane-associated receptors (i.e. shedding) or direct synthesis of truncated forms. Soluble receptor concentration, \(C_{SS,sR}\), is the concentration of the soluble forms of the receptor. In multi-compartment models, soluble receptor can be set on a per-compartment basis.
Soluble Receptor Concentration in Assess
When soluble forms of the receptor have been reported, the central compartment concentration can be set to concentrations measured in the plasma or serum. Such data is often measured by ELISA or other immunoassays or mass spectrometry.
For other compartments (peripheral, disease, or tox), direct measurements in the tissue of interest or common assumptions may be used. In the absence of direct measurements, a common assumption is equal concentration as reported in the plasma. Scanning across a range of values can be used to determine the importance of this parameter and whether experimental measurements may be a priority.
When soluble forms of the receptor are not relevant, this parameter should be set to 0, the default value.