Indomethacin

Soluble cholesterol, Atropine sulfate, Yohimbine hydrochloride and 2-aminoethoxydiphenyl borate (2-APB) were also purchased from Sigma Chemical Company, St Louis, USA. Acetylcholine chloride and Indomethacin were obtained from Abbot, France. All physiological solutions were prepared on the day of the experiment.

Twenty-eight rats were divided into four groups: control (Con, n = 7), Paricalcitol alone (PC, n = 7), contrast alone (CONT, n = 7), and Paricalcitol prior to contrast infusion (PC+CONT, n = 7). We used a previously published protocol to produce CI-AKI [21 (link)]. Rats were initially given indomethacin (10 mg/kg; Wako Pure Chemical Corporation, Osaka, Japan), which was followed by N-ω nitro-L-arginine methyl ester (10 mg/kg; Wako Pure Chemical Corporation) and ioversol (8.3 mL/kg of organically bound iodine) via intravenous injection into the tail vein 15 and 30 min later, respectively. Paricalcitol 0.3 μg/kg (Abbott Co., Seoul, Korea) was given intraperitoneally 24 h and 30 min before indomethacin (Supplementary Fig. 1). Controls received phosphate-buffered saline (PBS). Rats were sacrificed 6, 12, 24, and 48 h after ioversol injection, and blood and kidney tissues were harvested.