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Dear Lei Sun,
It appears from your first question that you determined the volume of
distribution from your IV data and applied it to your infusion data and
found a discrepancy in the infusion fits when your input IV doses were
presented in =B5g/kg or =B5g units. I think your source of confusion lies i=
n
the units of the dose you are inputing into your software. When the dose is
entered as =B5g/kg the corresponding volumes that are estimated will also be
normalized to the body weight of the animals i.e. will be presented as mL/kg
by the software. Correspondingly, when the dose is entered as =B5g the outpu=
t
by the software for the volumes will be in mL units. Now the dose values you
input into the computer for your infusion data sets is not normalized to the
body weight of the animals (by your account 10.9 and 21.9 =B5g/min) and henc=
e
the mL/kg values of volume you obtained from the IV data cannot support the
fits for your infusion. Take home message---Keep your units consistent
throughout.
The dimensions for a zero order input constant are Conc. X time^-1. Whether
you normalize it to body weight is based on your experimental design and
your choice.
Anup Zutshi
Battelle Pulmonary Therapeutics
zutshi.at.battelle.org
(614) 424-5997 (Tel)
(614) 424-3268 (fax)
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Copyright 1995-2010 David W. A. Bourne (david@boomer.org)