Free choline in human plasma analysed by simple radio-enzymatic procedure: Age distribution and effect of a meal

Abstract

Ultrafiltration of plasma was shown to be a simple and rapid method to obtain a stable sample for direct measurement of free choline (Ch) in plasma by a radioenzymatic procedure. Free Ch was analysed in plasma from healthy volunteers fasted 12–15 h and 1 h after a meal. The free Ch concentration was found within narrow limits with a mean of 10.6 ± 0.4 μimol/1 in the fasted subjects and 11.5 ± 0.3 μMmol/l 1 h after a meal. The difference is significant (paired t test, P < 0.01, n = 23). Dietary influence on the free Ch concentration in human plasma is suggested. In three newborn infants (1–3 min post partum) the Ch concentration in plasma from the umbilical vein was 24.5 ± 1.9 μmol/1.

Key Words:

• choline
• radio-enzymatic analysis