Potent human uric acid transporter 1 inhibitors: in vitro and in vivo metabolism and pharmacokinetic studies

Abstract

Human uric acid transporter 1 (hURAT1; SLC22A12) is a very important urate anion exchanger. Elevated urate levels are known to play a pivotal role in cardiovascular diseases, chronic renal disease, diabetes, and hypertension. Therefore, the development of potent uric acid transport inhibitors may lead to novel therapeutic agents to combat these human diseases. The current study investigates small molecular weight compounds and their ability to inhibit 14 C-urate uptake in oocytes expressing hURAT1. Using the most promising drug candidates generated from our structure-activity relationship findings, we subsequently conducted in vitro hepatic metabolism and pharmacokinetic (PK) studies in male Sprague-Dawley rats. Compounds were incubated with rat liver microsomes containing cofactors nicotinamide adenine dinucleotide phosphate and uridine 5′-diphosphoglucuronic acid. In vitro metabolism and PK samples were analyzed using liquid chromatography/mass spectrometry-mass spectrometry methods. Independently, six different inhibitors were orally (capsule dosing) or intravenously (orbital sinus) administered to fasting male Sprague-Dawley rats. Blood samples were collected and analyzed; these data were used to compare in vitro and in vivo metabolism and to compute noncompartmental model PK values. Mono-oxidation (Phase I) and glucuronidation (Phase II) pathways were observed in vitro and in vivo. The in vitro data were used to compute hepatic intrinsic clearance, and the in vivo data were used to compute peak blood concentration, time after administration to achieve peak blood concentration, area under the curve, and orally absorbed fraction. The experimental data provide additional insight into the hURAT1 inhibitor structure-activity relationship and in vitro-in vivo correlation. Furthermore, the results illustrate that one may successfully prepare potent inhibitors that exhibit moderate to good oral bioavailability.

Inhibition of arginase via jugular infusion of Nω-hydroxy-nor-l-arginine inhibits casein synthesis in lactating dairy cows

“…In addition to being the substrate for protein synthesis, some AA can regulate physiological function of cells by modulating the expression of protein carriers (Wempe et al, 2012b). In the present study, no difference in SLC7A1, SLC7A2, SLC7A6, and SLC7A7 expression was observed among treatments.…”

HIV-1 integrase tetramers are the antiviral target of pyridine-based allosteric integrase inhibitors

“…Next, we evaluated the metabolic stability of (-)-KF116 using rat and human liver microsomes (Figure 7—figure supplement 1B). We probed in vitro Cytochrome (CYP) P450 activity in the presence of co-factor NADPH (Wempe and Anderson, 2011; Wempe et al, 2012a; Wempe et al, 2012b) and monitored ALLINI stability by LC-MS. In vitro half-life measurements and calculated intrinsic clearance values in Figure 7—figure supplement 1B show that control compounds Verapamil, Domperidone and Chlorpromazine were metabolized as expected while ALLINIs displayed excellent metabolic stability toward CYP oxidation with (-)-KF116 exhibiting superior properties compared with racemic KF116 and quinoline-based BI224436.…”

Physiology of Hyperuricemia and Urate-Lowering Treatments

“…Lesinurad (Zurampic®) is the first novel uricosuric to reach the market since benzbromarone ( 94 ). The primary mechanism of action of lesinurad derives from inhibition of URAT1, although it is also reported to be an inhibitor of OAT4 which could also potentially contribute to its efficacy; however, it is reported to be selective over related transporters such as OAT1 and OAT3 which may avoid some of the drug-drug interaction liabilities of non-selective compounds such as probenecid ( 94 , 253 – 255 , 273 ).…”

“…This is more potent than lesinurad which has been reported to have a URAT1 IC 50 of 3.4 μM. Verinurad completed a Phase I clinical trial, in Japanese patients with gout or with asymptomatic hyperuricemia, which was designed to demonstrate its urate lowering effects ( 94 , 278 ). Doses ranging from 5 to 12.5 mg per day were given and resulted in >60% decrease in the mean sUA levels in patients.…”