Citalopram

The proximal tubular cell line HK-2 (human kidney 2, CRL-2190) of the normal adult human kidney was purchased from the American Type Culture Collection (ATCC). Cells were maintained in keratinocyte serum-free (KCSF) medium with 40 μg/mL bovine pituitary extract (Gibco BRL, Grand Island, NY, USA) and 5 ng/mL recombinant epidermal growth factor and incubated at 37℃ and 5% CO₂ in a humidified chamber. The cultured medium was replaced every 2–3 d for the cultured cells. A density of approximately 1 × 10⁵ HK-2 cells was seeded separately in each well of 96-well plates before treatment with test compounds and then maintained at 37℃ and 5% CO₂ in a humidified incubator for 1 d. All test chemicals, including dobutamine, dofetilide, citalopram, and ritodrine (MedChemExpress, Monmouth Junction, NJ, USA), were dissolved in dimethyl sulfoxide (DMSO) before the cell viability test.

In all, 18 compounds with different physiochemical properties were selected for this study. Antipyrine, ganciclovir, ofloxacin, 4‐aminoAntipyrine, lamotrigine, theophylline, citalopram, digoxin, quinidine, pemetrexed, atenolol, carbamazepine, propranolol, and diltiazem were purchased from MedChemExpress (Monmouth Junction). Acetaminophen was purchased from Sigma‐Aldrich. Fexofenadine and sumatriptan were purchased from Tokyo Chemical Industry. Cimetidine was purchased from National Institute for the Control of Pharmaceutical and Biological Products. All the other chemicals were of the HPLC grade or better.