Atrial natriuretic peptide eia kit

SCN⁻ concentrations were quantified by ion-exchange chromatography^{26 (link),87 (link)}. Serum samples were mixed 1:1 (v/v) with acetonitrile, followed by centrifugation (5000g, 4 °C, 7 min) to remove precipitated proteins. The supernatant was subsequently filtered through 0.2 μm centrifuge filters (5000g, 4 °C, 3 min; Pall Nanosep MF, 500 μL capacity). Samples (25 μL) were then injected on to an IonPac AS16 column (4 × 250 mm) via an AG16 guard column (4 × 50 mm) fitted into a Dionex chromatography system consisting of an AS3500 autosampler, GP40 gradient pump, ASRS 300 anion suppressor (4 mm) in AutoSuppression recycle mode, and an ED40 electrochemical detector with DS3 detector stabilizer. Ions were eluted over 12 min with 50 mM potassium hydroxide in water with a flow rate of 1.5 mL min⁻¹ and a suppressor current of 186 mA. Peak areas were quantified using Chromeleon Chromatography Studio software (version 7), against a standard curve generated using commercial NaSCN (0–200 μM).
ANP, BNP, CRP, and galectin-3 were quantified using commercial kits (Atrial Natriuretic Peptide EIA Kit, Brain Natriuretic Peptide EIA Kit, and rat C-Reactive Protein ELISA Kit, all from Sigma-Aldrich; and rat Galectin-3 ELISA from Ray Biotech) in accordance with the manufacturer’s instructions.

Body composition was determined by NMR spectroscopy using a TD-NMR miniSpec Live Mice Analyzer (Bruker Optics). For metabolic phenotyping, mice were single-housed in a laboratory animal monitoring system (PhenoMaster, TSE Systems) with ad libitum access to HFD and water. Food intake, locomotor activity, and oxygen consumption rate were determined for light and dark phase on four consecutive days. Body temperature was measured using a rectal probe RET-3 (Physitemp). For glucose tolerance test, mice were injected intraperitoneally (ip) with 1.6 g per kg body weight following a 6 h fast. For insulin tolerance test, mice were injected ip with 0.75 IU insulin per kg body weight following a 4 h fast. Blood glucose was determined by Wellion CALLA glucometer (Med Trust). Plasma lipid parameters were determined using following commercial kits: FA (NEFA-HR2, Wako Diagnostics), TAG (Infinity triglycerides, Thermo Fisher Scientific), glycerol (free glycerol reagent, Sigma-Aldrich), total cholesterol (cholesterol CHOD-PAP kit; Roche Applied Science), and ketone bodies (β-Hydroxybutyrate Assay Kit, Cayman Chemical). Plasma insulin levels were determined using Ultra-Sensitive Mouse Insulin ELISA Kit (Crystal Chem). Plasma ANP levels were determined using Atrial Natriuretic Peptide EIA Kit (Sigma-Aldrich). Plasma FGF21 levels were determined using Rat/Mouse FGF21 ELISA Kit (Sigma-Aldrich).