Alterations of valsartan pharmacokinetics in a rodent model of metabolic dysfunction–associated steatohepatitis

Valsartan (VAL) is commonly prescribed for patients with cardiovascular disease (CVD) to lower blood pressure, reduce heart failure risk, and prevent heart attacks or strokes by blocking the effects of angiotensin II. Many patients with CVD also suffer from metabolic dysfunction–associated steatohepatitis (MASH), which disrupts several xenobiotic transporters, affecting the pharmacokinetics of numerous drugs. Medications used in patients to treat comorbidities associated with MASH may be subject to this altered disposition and potential toxicity. This study aimed to assess how MASH alters the pharmacokinetics of VAL using a rodent model that mimics human MASH. MASH was induced in rats via a methionine- and choline-deficient (MCD) diet. Rats received VAL—a substrate of organic anion–transporting polypeptide (OATP) 1B1/1B3 and reported for multidrug resistance–associated protein-2—(2 mg/kg) through intravenous injection to isolate hepatic transport processes, and bile, serum, and liver concentrations measured using liquid chromatography–tandem mass spectrometry. Consistent with MASH progression, MCD rats presented with more gross pathology, including increased liver-to-body weight ratios, along with macrosteatosis, hepatocyte ballooning, and lobular inflammation. In MCD rats, the expression of Oatp1b2 was significantly reduced, and Mrp2 was internalized, resulting in higher systemic exposure to VAL compared with controls. Additionally, cumulative biliary excretion of VAL was lower in MCD rats. To further assess VAL disposition in MASH, transport kinetics were evaluated in human embryonic kidney 293 cells overexpressing OATP1B1 or OATP1B3, revealing similar affinity for VAL between both transporters. These findings suggest that changes in OATP function in MASH may alter VAL pharmacokinetics, which may have implications for personalized treatments. Significance Statement: Although expression of drug transporters in metabolic dysfunction–associated steatohepatitis (MASH) has been explored, the combined effect between MASH and genetic loss of transporters on the disposition of sartan drugs has not been determined. This study applied liquid chromatography–tandem mass spectrometry analyses and immunohistological staining to assess drug disposition and identify alterations to drug transporters in rodents on a methionine- and choline-deficient diet. The observations made in this study have significant implications regarding its disposition in the context of hepatic dysfunction associated with MASH.