Determination of Rate of [3H-methyl]-choline Incorporation into Cellular Lipids and Non-lipid Metabolites

Abstract

The choline-containing phospholipid, phosphatidylcholine (PtdCho) is the most common mammalian phospholipid found in cell membrane (Ide et al., 2013). It is also a component of intracellular signalling pathways (Cui and Houweling, 2002). Herein is described a measure of the rate of accumulation of choline by lipid soluble PtdCho and lyso-Ptdcho which can further be discriminated by chromatographic analysis (Smith and Phyu, 2016). Determination of the accumulation of [3H-methyl]-choline into water-soluble components is also described. The procedure could be used to measure the effect of drugs and other factors on choline incorporation into phospholipids. After exposure of cells to test conditions (e.g., drugs) adherent cells in tissue culture flasks are incubated with radiolabelled [3H-methyl]-choline in medium for 15 min (pulse). The [3H-methyl]-choline is then rapidly removed and incubation continued in the presence of non-radioactive medium (chase). Cellular distribution of [3H-methyl] is then determined by cell fractionation and measurement of radioactivity in the lipid and non-lipid cellular components.