Urinary excretion of carnitine in man

A convenient assay procedure for urinary carnitine is described. Urinary excretion of carnitine is determined in human subjects in various experimental states. Average excretions by this procedure were 59.3+/-3.3 mg. per day in men and 44.1+/-2.9 mg. per day in women. Carnitine excretion had a wide variation in women during the menstrual cycle and reached a maximum at the time of ovulation, but the excretion was relatively constant in men. Marked increases in carnitine excretion were observed in the states with increased lipolysis induced by fasting or ACTH injection. This finding suggests that lipid mobilization might be reflected in the excretion of carnitine in urine.