Estimation of physiological volumes in the isolated perfused porcine skin flap.

A requirement for pharmacokinetic modeling of isolated perfused organ systems used for in vitro to in vivo extrapolations is a measure of the organ's physiological spaces. Two methods were employed to estimate intravascular and extracellular spaces in four isolated perfused porcine skin flaps (IPPSF) from 2 pigs. One of these methods used regression techniques based on a one-compartment model, and was found to be a good estimator of intravascular volume only. The other method was a non-parametric numerical integration technique, and was found to give reasonable estimates for both intravascular and extracellular volumes. The latter method's estimate for extracellular space was 0.20 +/- 0.03 mL/g, and the estimated vascular space by both methods was 0.08 +/- 0.01 mL/g.