Lactisole

The following chemicals were used: Dulbecco’s MEM, sodium chloride, 2-Mercaptoethanol (Merck KGaA, Darmstadt, Germany), FBS superior, L-glutamine, Penicillin (10,000 U/mL)/streptomycin (10,000 U/mL), Trypsin/EDTA solution (Bio & Sell GmbH, Feucht, Germany), Dimethyl sulfoxide (DMSO), HEPES, Potassium chloride, sodium hydroxide, calcium chloride dehydrate, D-glucose (VWR International GmbH, Darmstadt, Germany), D-luciferin (beetle) monosodium salt (Promega, Madison, WI, USA), Bordetella pertussis toxin, L-Glutamic acid monosodium salt monohydrate (Santa Cruz Biotechnology, Dallas, TX, USA), Forskolin (Biomol GmbH, Hamburg, Germany), Lactisole (Cayman Chemicals, Ann Arbor, MI, USA), fMLF (Tokio Chemical Industry, Tokyo, Japan), mGluR2 antagonist 1 (CAS: 1432728-49-8; Biozol GmbH, Eching, Germany), metabotropic glutamate receptor 2/3 agonist LY379268 (Tocris Bioscience, Bristiol, UK), Gibco RPMI 1640 containing L-glutamine (Thermo Fisher Scientific, Waltham, MA, USA), Probenecid (Sigma-Aldrich, St. Louis, MO, USA), Pluronic^® F-127 (AAT Bioquest Inc., Sunnyvale, CA, USA), Fluo-4 AM (Bio-Techne, Minneapolis, MN, USA). Calcium buffer was composed of 140 mM NaCl, 20 mM HEPES, 5 mM KCl, 1.8 mM CaCl₂, and 0.5 mM D-glucose, adjusted pH 7.4.

Primary glomerular microvascular endothelial cells (GMVEC), purchased from Cell Systems (Kirkland, WA, USA), were cultured in complete classic medium (#4Z0-500) supplemented with culture boost. The passage number was used between 3 to 7. This primary cell line was utilised as any other relevant cell lines are immortalised rather than human primary cells and were therefore not appropriate. Endothelial growth factor (VEGF-A₁₆₅) was purchased from Thermo-Fisher (Paisley, UK). Pure and analytical grade artificial sweeteners, aspartame, saccharin, and sucralose, the CCK-8 cell viability kit, FITC-dextran, N-Methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA), methanol, and ethyl acetate were purchased from Sigma-Aldrich (Dorset, UK). Lactisole, a sweet taste inhibitor, was purchased from Cayman Chemical (Ann Arbor, MI, USA). The cAMP-Screen Direct System kit and GSH Bioxytech activity kit were purchased from Applied Biosystems and Merck Millipore respectively. DharmaFECT™ reagent and siRNA (T1R3 and non-specific, scrambled) were purchased from Dharmacon (Cambridge, UK). Anti VE-cadherin and fluorescent secondary antibodies, deuterated sucralose, and sucralose-D6 (SC-220145) were purchased from Santa Cruz Biotechnology (Santa Cruz, CA, USA). 2,7-dichlorodihydrofluorescein diacetate (DCFDA) was purchased from Abcam (Cambridge, UK).

All compounds used for sensory evaluations were obtained in food grade (FG) quality. Citric acid, ethanol, monosodium glutamate, sodium chloride and sucrose were purchased from local supermarkets and pharmacies (Vienna, AT). Caffeine (anhydrous, 99 %, FG, W222402) and NHDC (≥  96 %, FG, W381101) was obtained from Merck KGaA (Darmstadt, DE). Acesulfame K (>  98 %), aspartame (> 99 %), cyclamate (>  99 %), lactisole (> 99 %), iron lactate-IIhydrate, and tannic acid (nat.) were kindly provided in FG quality by the Symrise AG (Holzminden, DE). Compounds used in cell experiments were aspartame, cyclamate (sodium salt, ≥ 99 %), neohesperidin dihydrochalcone (≥  95 %), Acesulfame K (≥  99 %) from Sigma-Aldrich; lactisole (sodium salt, ≥ 98 %) from Cayman Chemical.