Phosphotungstic acid mg2 method

The total cholesterol, triglycerides and glucose plasma concentrations were determined by enzymatic colorimetric methods (Randox Laboratories Ltd., Crumlin, Antrim, U.K.). Sphingomyelin (SM) concentrations were assessed by a commercial colorimetric test (Cayman Chemical, Ann Arbor, MI, USA). The phosphotungstic acid−Mg²⁺ method (Randox Laboratories Ltd., Crumlin, Antrim, U.K.) was used to precipitate the apo B-containing lipoproteins (i.e., Very Low-Density Lipoproteins/Low-Density Lipoprotein); then HDL-C and HDL-Tg plasma concentrations were determined in the supernatant fraction by the same enzymatic colorimetric methods (Randox Laboratories Ltd., Crumlin, Antrim, U.K.), whereas HDL-phospholipids (HDL-Pho) were determined with a commercial kit (Wako Chemicals, Richmond, VA, USA).
HDL-SM and non−HDL-SM were determined by analytical ultracentrifugation. Plasma samples were adjusted at a density of 1.063 g/mL with solid KBr. The bottom (HDL) and top (non-HDL lipoproteins) of the tubes after ultracentrifugation were quantitatively recovered and analyzed using the same colorimetric assay kit mentioned above (Cayman Chemical, Ann Arbor, MI, USA). All the determinations were performed following the manufacturer’s instructions.

The total cholesterol, triglycerides, and glucose plasma concentrations were determined by enzymatic colorimetric methods (Randox Laboratories, Antrim, UK). The phosphotungstic acid-Mg²⁺ method (Randox Laboratories, Antrim, UK) was used to precipitate the apo B-containing lipoproteins (i.e., VLDL/LDL, very low-density lipoproteins/low-density lipoproteins) in the plasma. In the supernatant fraction, HDL-C, high-density lipoproteins-triglycerides (HDL-Tg), and high-density lipoproteins-phospholipids (HDL-Ph) plasma concentrations were determined by enzymatic colorimetric methods (Randox Laboratories, Antrim, UK and Wako Chemicals, Richmond, VA, USA). Apo A-I plasma concentration was determined by a commercial ELISA kit (Mybiosource, San Diego, CA, USA). All the determinations were performed following the instructions of the manufacturers.