Quantitative Characterization of Clinically Relevant Drug-Metabolizing Enzymes and Transporters in Rat Liver and Intestinal Segments for Applications in PBPK Modeling

ABSTRACT: Rats are extensively used preclinical models for assessing drug pharmacokinetics (PK) and tissue distribution; however, a successful translation of the rat data requires information on the differences in drug metabolism and transport mechanisms between rats and humans. To partly fill this knowledge gap, we quantified clinically-relevant drug-metabolizing enzymes and transporters (DMET) in the liver and different intestinal segments of Sprague Dawley rats. The levels of DMET proteins in rats were quantified using global proteomics-based total protein approach (TPA) and targeted proteomics. The abundance of DMET proteins was largely comparable using quantitative global and targeted proteomics. Global proteomics-based TPA was able to detect and quantify a comprehensive list of 69 DMET proteins in the liver and 36 DMET proteins in the intestinal segments of SD rats without the need for peptide standards. Cytochrome P450 (Cyp) and UDP-glycosyltransferase (Ugt) enzymes were mainly detected in the liver with the abundance ranging from 8 to 6502, and 74 to 2557 pmol/g tissue. P-gp abundance was higher in the intestine (124.1 pmol/g) as compared to the liver (26.6 pmol/g) using the targeted analysis. Breast cancer resistance protein (Bcrp) was most abundant in the intestinal segments, whereas organic anion transporting polypeptide (Oatp) 1a1, 1a4, 1b2 and 2a1, and multidrug resistance protein (Mrp) 2 and 6 were predominantly detected in the liver. To demonstrate utility of these data, we modeled digoxin PK by integrating protein abundance of P-gp and Cyp3a2 into a physiologically-based PK (PBPK) model constructed using PK-Sim software. The model was able to reliably predict the systemic as well as tissue concentrations of digoxin in rats. These findings suggest that proteomics-informed PBPK models in preclinical species can allow mechanistic PK predictions in animal models including tissue drug concentrations.

INSTRUMENT(S): Xevo TQ-XS, Q Exactive HF

ORGANISM(S): Rattus Norvegicus (rat)

TISSUE(S): Liver, Colon, Kidney

SUBMITTER: Bhagwat Prasad  

LAB HEAD: Bhagwat Prasad

PROVIDER: PXD039271 | Pride | 2025-02-05

REPOSITORIES: pride