TABLE 1

Parameter estimates from modeling of tissue concentrations of tracer

The tissue tracer concentration was assumed to consist of two parts: 1) linear nonspecific binding determined by the plasma tracer concentration (C_p) and a partitioning constant for nonspecific binding (K_p,ns) and 2) nonlinear binding to the target determined by C_p, the dissociation constant (K_d) and the receptor density (B_max). K_d is estimated from total C_p, if corrected for plasma protein binding K_d is 0.21 ± 0.12 nM. Precision of the estimates is expressed as S.E. The root mean squared error was 1.2 nM.