Background: Carnitine is reported to improve insulin resistance and reduce oxidative stress. Hyperglycemia and increased oxidative stress are well known to promote the production of advanced glycation end products (AGEs) that can lead to arteriosclerosis in patients with maintenance hemodialysis (HD). In the present study, we aimed to determine whether decreased level of serum carnitine acceler...

1. Carnitine acetyltransferase (EC 2.3.1.7) activity in sheep liver mitochondria was 76nmol/min per mg of protein, in contrast with 1.7 for rat liver mitochondria. The activity in bovine liver mitochondria was comparable with that of sheep liver mitochondria. Carnitine palmitoyltransferase activity was the same in both sheep and rat liver mitochondria. 2. The [free carnitine]/[acetylcarnitine] ...

OBJECTIVES L-carnitine and dehydro-epiandrosterone (DHEA) independently promote mitochondrial energy metabolism. We therefore wondered if an age-related deficiency of L-carnitine or DHEA may account for the declining energy metabolism associated with age. METHODS we evaluated serum levels of L-carnitine and the sulphated derivative of DHEA (DHEAS) in cross-sectional study of 216 healthy adult...

BACKGROUND Functional carnitine deficiency [as indicated by an abnormal acyl-carnitine/free-carnitine (AC:FC) ratio] is commonly seen in patients with end-stage renal disease (ESRD), resulting in significant clinical detriments including anaemia, cardiomyopathy and muscle weakness. Nocturnal haemodialysis (NHD) (5-6 sessions per week, 8 h per treatment) has been reported to reverse several surr...

Effect of starvation or ACTH injection on the urinary level and profile of L-carnitine and its derivatives was studied in four healthy adult men or in a normal child and two patients with myopathy, respectively. Mean total L-carnitine level in the control urine sample obtained before starvation was 389 +/- 34 mumol . man . day. The percentage distribution was found to be 46% for free-, 9% for a...

Introduction: In order to clarify the characteristics of different administration routes and to optimize the dosage, carnitine kinetics was investigated under oral and intravenous supplementation. Methods: Lcarnitine was administered orally (900mg) for 12months, intravenously (1000 mg) for 3months and (500mg) for 3months sequentially in 18 chronic hemodialysis patients. Plasma free and acyl car...

The site of action of 3-(2,2,2-trimethylhydrazinium) propionate (THP), a new cardioprotective agent, was investigated in mice and rats. I.p. administration of THP decreased the concentrations of free carnitine and long-chain acylcarnitine in heart tissue. In isolated myocytes, THP inhibited free carnitine transport with a Ki of 1340 microM, which is considerably higher than the observed serum c...

Proteus sp. is able to catalyse the reversible transformation of crotonobetaine into L(-)-carnitine during aerobic growth. Contrary to other Enterobacteriaceae no reduction of crotonobetaine into gamma-butyrobetaine could be detected in the culture supernatants. Activities of L(-)-carnitine dehydratase, carnitine racemasing system and crotonobetaine reductase could be determined enzymatically i...

BACKGROUND Analysis of carnitine and acylcarnitines by tandem mass spectrometry (MS/MS) has limitations. First, preparation of butyl esters partially hydrolyzes acylcarnitines. Second, isobaric nonacylcarnitine compounds yield false-positive results in acylcarnitine tests. Third, acylcarnitine constitutional isomers cannot be distinguished. METHODS Carnitine and acylcarnitines were isolated b...

other laboratories (6), it makes economic sense to consolidate to one platform that can perform multiple assays without operator intervention. We have extended this method to include measurements of acetyl carnitine (data not shown). In this case, a mixture of labeled carnitines are added to plasma, and concentrations are calculated from calibration curves for free, acetyl, and total carnitine....