Clofibrate

All experimental procedures were approved by the North Carolina State University Animal Care and Use Committee. Ten male newborn pigs (Landrace × Yorkshire × Duroc), 2 from each of 5 L, were used in this experiment. The selected newborn piglets (Body weight (BW) = 1.61 ± 0.06 kg) were allocated randomly into two treatments: control and clofibrate. The control piglets were orogastrically gavaged with 2 mL of 2% Tween 80, and the clofibrate-treated piglets were orogastrically gavaged to 2 mL of 2% Tween 80 containing clofibrate (75 mg/kg BW; Cayman Chemicals, Ann Arbor, MI, USA) at 8:00 a.m. of each day for 4 days as described previously [23 (link)]. All piglets were kept with their dams and siblings at the North Carolina State University Swine Educational Unit in Raleigh, North Carolina during the experiment. The piglets were euthanized by AVMA-approved electrocution on Day 4 after gavaging and feeding, and kidney and blood samples were collected. Fresh kidney samples were collected and stored in a homogenate buffer, and extra kidney samples were immersed in liquid nitrogen and stored at −80 °C. The blood was sampled with vacutainer containing sodium heparin and centrifuged at 2500 rpm × 10 min. The plasma was collected and stored at −20 °C.

Clofibrate was purchased from Cayman Chemical Company (Ann Arbor, MI. USA). [1-¹⁴C]-oleic acid (C18:1) and [1-¹⁴C]-lignoceric acid (C24:0) were purchased from American Radiolabeled Chemicals, Inc. (St. Louis, MO. USA). 2-(4-Chlorophenoxy)-2-methylpropionic acid ethyl ester, 2-(4-chlorophenoxy)-2-methylpropionic acid, 4-chlorophenylacetic acid, peroxidase and all other chemicals were obtained from Sigma-Aldrich (St. Louis, MO. USA).