Compartments to enter into the initial.amounts list includes Agutlumen,
Aart, Aven, Alung, Agut, Aliver, Akidney, and Arest.
Parameters are generated by a call to parameterize_pbtk
.
When species is specified as rabbit, dog, or mouse, the function uses the
appropriate physiological data(volumes and flows) but substitues human
fraction unbound, partition coefficients, and intrinsic hepatic clearance.