Urinary carnitine excretion is decreased by supplemental choline in humans and guinea pigs. In guinea pigs, the decreased excretion is associated with increased carnitine concentrations in skeletal muscle and decreased body fat. This study evaluated the effect of choline supplementation at various levels (0, 2, 5, or 10 g choline per kg diet) on feed intake, intestinal carnitine retention, whole body carnitine, and renal reabsorption of carnitine in guinea pigs. Choline supplemented animals excreted < half the carnitine as unsupplemented after day 2 of the study, due to an increase in fractional tubular reabsorption of carnitine. However, there was no significant effect of different doses of choline on urinary carnitine excretion. Carnitine concentrations were higher in gut, muscle, and carcasses in the choline supplemented animals. There was no difference in carnitine concentrations of feces or gut contents. This study demonstrated that choline preserves body carnitine stores through increased renal reabsorption.
- Guinea pig
- Renal reabsorption
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Nutrition and Dietetics