Choline-induced carnitine conservation by increased fractional tubular reabsorption of carnitine in guinea pigs

Analysis of Choline, Carnitine, Acetylcarnitine and Acetylcholine in Animal Feeds, Blood and Urine Using Ion Chromatography Coupled with Tandem Mass Spectrometry

A simple and sensitive method was proposed for choline, carnitine, acetylcarnitine (ACa) and acetylcholine (ACh) separation in feed, blood and urine of animals by using ion chromatography (IC) and detection by tandem mass spectrometry (MS/MS). Analytes were extracted using a mixture of acetonitrile and water, purified by C18 solid-phase extraction columns, separated via IC with an IonPac SCS-1 column and detected by an MS/MS detector by using isotopic internal standards for quantification. The effects of different chromatographic parameters on the separation were also investigated. Under optimal conditions, the recovery was >90%, with the relative standard deviations of <15%. The proposed method was highly reliable for the simultaneous determination of choline, carnitine, ACa and ACh in feed, blood and urine.

Timing of initiation and duration of feeding rumen-protected choline affects performance of lactating Holstein cows

Objectives were to evaluate the effects of altering timing of initiating and duration of supplementing rumen-protected choline (RPC) on lactation performance in dairy cows. The hypothesis was that RPC increases yields of milk and milk components, regardless of when supplementation is initiated, and that the effects of supplementing RPC starting prepartum and continuing post-transition would be additive. Cows at 241 ± 2.2 d of gestation were blocked by parity group (49 entering lactation 2, 50 entering lactation >2) and 305-d milk yield and, within block, assigned randomly to 1 of 4 treatments arranged as a 2 × 2 factorial with 2 levels of choline in transition, from 21 d pre- to 21 d postpartum, and 2 levels of choline in post-transition, from 22 to 105 d postpartum. The 2 levels of RPC supplemented were either 0 g/d or 12.9 g/d of choline ion fed as 60 g/d of an RPC product that was top-dressed onto the total mixed ration. Thus, treatments were as follows: NN (n = 25): no choline in transition or post-transition; NC (n = 25): no choline in transition and choline in post-transition; CN (n = 25): choline in transition and no choline in post-transition; CC (n = 24): choline in transition and in post-transition. Prepartum, treatments were supplemented (mean ± SD) for the last 18.8 ± 5.7 and 19.2 ± 5.0 d of gestation in treatments with 0 or 12.9 g/d of choline ion, respectively. Supplementing RPC prepartum did not affect dry matter intake (DMI), body weight (BW), or body condition score (BCS) in the last 3 weeks of gestation. Likewise, RPC did not affect the yield or the composition of colostrum. Supplementation with RPC during transition increased fat percent by 0.02 percentage units, fat yield by 0.16 kg/d, and energy-corrected milk (ECM) by 3.1 kg/d in the first 21 d postpartum, and increased fat yield by 0.10 kg/d and ECM by 2.4 kg/d from 22 to 105 d postpartum. Supplementing RPC during transition did not affect DMI postpartum, but it improved feed efficiency, and cows produced 0.11 kg/d more ECM per kg of DMI. Changes in BW and BCS during the first 21 d postpartum did not differ between treatments. Cows fed RPC during transition had more negative net energy balance and 0.1 unit smaller BCS in the first 105 d postpartum than non-supplemented cows. Supplementing RPC in post-transition did not influence productive performance in dairy cows, and choline supplementation during transition or post-transition did not affect measures of reproduction. Collectively, supplementing RPC to supply 12.9 g/d of choline ion benefited productive performance in dairy cows when supplementation occurred during the transition period, but no additional benefit was observed from supplementing RPC past 22 d postpartum.

Carnitine and choline supplementation with exercise alter carnitine profiles, biochemical markers of fat metabolism and serum leptin concentration in healthy women

We sought to determine the effects of supplementary choline, carnitine and a combination of the two with or without exercise on serum and urinary carnitine and biochemical markers of fatty acid oxidation in healthy humans. Nineteen women were placed in three groups: 1) placebo, choline or carnitine preloading period of 1 wk followed by 2) supplementation with choline plus carnitine during wk 2-wk 3 and 3) all groups exercised in wk 3. Although there were no changes in the placebo group, serum and urinary carnitine decreased in the choline-supplemented group during wk 1. Introduction of carnitine to the choline group restored serum and urinary carnitine. Serum and urinary carnitine increased during wk 1 in the carnitine-supplemented group and, although the introduction of choline to this group depressed serum and urinary carnitine, they remained significantly greater than control. Serum beta-hydroxybutyrate and serum as well as urinary acetylcarnitine were elevated by the supplements. A mild exercise regimen increased the concentration of serum beta-hydroxybutyrate, and serum and urinary acylcarnitines; it also decreased serum leptin concentrations in all groups. The effects of supplements were sustained until wk 2 after cessation of choline plus carnitine supplementation and exercise. We conclude that the choline-induced decrease in serum and urinary carnitine is buffered by carnitine preloading, and these supplements shift tissue partitioning of carnitine that favors fat mobilization, incomplete oxidation of fatty acids and disposal of their carbons in urine as acylcarnitines in humans.