| tissue.data {httk} | R Documentation |
Tissue composition and species-specific physiology parameters
Description
This data set contains values from Schmitt (2008) and Ruark et al. (2014) describing the composition of specific tissues and from Birnbaum et al. (1994) describing volumes of and blood flows to those tissues, allowing parameterization of toxicokinetic models for human, mouse, rat, dog, or rabbit. Tissue volumes were calculated by converting the fractional mass of each tissue with its density (both from ICRP), lumping the remaining tissues into the rest-of-body, excluding the mass of the gastrointestinal contents.
Usage
tissue.data
Format
A data.frame containing 406 rows and 5 columns.
| Column | Description |
| Tissue | The tissue being described |
| Species | The species being described |
| Reference | The reference for the value reported |
| variable | The aspect of the tissue being characterized |
| value | The value for the variable for the given tissue and species |
Details
Many of the parameters were compiled initially in Table 2 of Schmitt (2009). The full list of tissue variables described is:
| Variable | Description | Units |
| Fcell | Cellular fraction of total tissue volume | fraction |
| Fint | Interstitial fraction of total tissue volume | fraction |
| FWc | Fraction of cell volume that is water | fraction |
| FLc | Fraction of cell volume that is lipid | fraction |
| FPc | Fraction of cell volume that is protein | fraction |
| Fn_Lc | Fraction of cellular lipid tht is neutral lipid | fraction |
| Fn_PLc | Fraction of cellular lipid tht is neutral phospholipid | fraction |
| Fa_PLc | Fraction of cellular lipid tht is acidic phospholipid | fraction |
| pH | Negative logarithm of H+ ion concentration | unitless |
| Density | Tissue density | g/cm^3 |
| Vol | Tissue volume | L/kg |
| Flow | Blood flow to tissue | mL/min/kg^(3/4) |
New tissues can be added to this table to generate their partition coefficients.
Author(s)
John Wambaugh, Robert Pearce, and Nisha Sipes
References
Birnbaum L, Brown R, Bischoff K, Foran J, Blancato J, Clewell H, Dedrick R (1994). “Physiological parameter values for PBPK models.” International Life Sciences Institute, Risk Science Institute, Washington, DC.
Ruark CD, Hack CE, Robinson PJ, Mahle DA, Gearhart JM (2014). “Predicting passive and active tissue: plasma partition coefficients: interindividual and interspecies variability.” Journal of pharmaceutical sciences, 103(7), 2189–2198.
Schmitt W (2008). “General approach for the calculation of tissue to plasma partition coefficients.” Toxicology in vitro, 22(2), 457–467.
Snyder WS (1974). “Report of the task group on reference man.” ICRP publication.
Wambaugh JF, Wetmore BA, Pearce R, Strope C, Goldsmith R, Sluka JP, Sedykh A, Tropsha A, Bosgra S, Shah I, others (2015). “Toxicokinetic triage for environmental chemicals.” Toxicological Sciences, 147(1), 55–67.
See Also
Examples
# We can add thyroid to the tissue data by making a row containing
# its data, subtracting the volumes and flows from the rest-of-body,
# and binding the row to tissue.data. Here we assume it contains the same
# partition coefficient data as the spleen and a tenth of the volume and
# blood flow:
new.tissue <- subset(tissue.data,Tissue == "spleen")
new.tissue[, "Tissue"] <- "thyroid"
new.tissue[new.tissue$variable %in% c("Vol (L/kg)",
"Flow (mL/min/kg^(3/4))"),"value"] <- new.tissue[new.tissue$variable
%in% c("Vol (L/kg)","Flow (mL/min/kg^(3/4))"),"value"] / 10
tissue.data[tissue.data$Tissue == "rest", "value"] <-
tissue.data[tissue.data$Tissue == "rest", "value"] -
new.tissue[new.tissue$variable %in% c("Vol (L/kg)",
"Flow (mL/min/kg^(3/4))"),"value"]
tissue.data <- rbind(tissue.data, new.tissue)