Assessment of the Effect of Age, Renal Function Status, and M-Cholinoblocker Biperidene Intake on Free Plasma Choline Concentrations

The use of high-performance liquid chromatography in combination with tandem mass spectrometry (HPLC-MS/MS) provides a selective determination of free choline in blood plasma. The instability of the measurement results is due to the residual activity of phospholipases that promote the hydrolysis of phosphatidylcholine ex vivo. The use of EDTA as an anticoagulant and compliance with the cold regime (≤4°C) from blood sampling to the supply of deproteinized and diluted plasma for analysis ensures the accuracy of the analysis (standard deviation not higher than 15%) within the linear range (0.5–10) μg/mL or (5–96) µM. Using a validated method of choline determination in plasma, it was found that the concentration of choline in plasma was (10.0 ± 2.2) μM in a group of people 20–40 years old with no identified diseases (n = 30), while the plasma choline concentration within 90 min rose from the baseline value (8.9 ± 1.3) to the mean value (19.1 ± 4.3) μM and remained at this level during the entire observation period of 72 h in volunteers of the same age and also without identified diseases (n = 50) after a single administration of M-cholinoblocker biperiden at a dose of 2 mg. It has also been confirmed that acute renal failure and advanced age are associated with increased plasma free choline concentrations.