• Asian-Australasian Journal of Animal Sciences
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• 제13권11호
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• pp.1568-1575
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• 2000

Growing pigs (N=25; 18 kg) were used to study effects of L-carnitine and protein intake on plasma carnitine, energy and carnitine balance, and carnitine biosynthesis. Corn-soybean meal basal diets containing low or high protein (13.6% or 18%) were formulated so that protein accretion would be limited by metabolizable energy (ME). Each basal diet was supplemented with 0 or 500 mg/kg L-carnitine and limit fed to pigs for 10 d in a balance trial. Final carnitine concentration was compared with weight/age matched pigs measured on d 0 to calculate carnitine retention rates. Supplementation of carnitine increased (p<0.01) plasma free carnitine (by 250%), short-chain (by 160%) and long-chain acyl-carnitine concentrations (by 80%) irrespective of blood sampling time (p<0.01). The proportion of long-chain carnitine esters decreased by 40% (p<0.01) by carnitine supplementation; whereas, the proportion of short-chain acyl-carnitine concentration was not changed (p>0.10). All criteria of energy balance were unaffected by L-carnitine (p>0.10). Total body carnitine retention was increased by 450% over unsupplemented controls (p<0.01). Carnitine biosynthesis rates in pigs fed diets without L-carnitine were estimated at 6.71 and $10.63{\mu}mol{\cdot}kg^{-1}{\cdot}d^{-1}$ in low protein and high protein groups, respectively. In supplemented pigs, L-carnitine absorption and degradation in the intestinal tract was estimated at 30-40% and 60-70% of L-carnitine intake, respectively. High protein feeding effect did not affected plasma carnitine concentrations, carnitine biosynthesis or carnitine retention (p>0.10). We conclude that endogenous carnitine biosynthesis may be adequate to maintain sufficient tissue levels during growth, but that supplemental dietary carnitine (at 500 ppm) sufficiently increased plasma acyl-carnitine and total body carnitine.

• Journal of Microbiology and Biotechnology
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• 제7권5호
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• pp.318-322
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• 1997

In order to isolate a microorganism having preferential degradation of D-carnitine from DL-carnitine, a bacterium assimilating D-carnitine as a sole carbon and energy source was isolated from soil by enrichment culture and partially identified as Enterobacter sp. Also, a mutant having lessened L-carnitine decomposition rates was selected with nitrosoguanidine mutagenesis, which led to decrease the specific activities of carnitine dehydrogenase (7.6-fold) and ${\beta}$-hydroxybutyrate dehydrogenase (9.5-fold) as compared to the wild strain. Meanwhile, optimal culture conditions for optical resolution of DL-carnitine were investigated. Under optimal conditions, 3.53 g/l L-carnitine was obtained from 20 g/l DL-carnitine, which corresponded to 35.3% L-carnitine yield and 97.9% optical purity.

• Asian-Australasian Journal of Animal Sciences
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• 제12권5호
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• pp.799-805
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• 1999

This study was conducted to investigate the effects of L-carnitine with different levels of lysine on performance of pigs weaned at 21 days of age. A total of 120 pigs were allotted into a $3{\times}2$ factorial design with three different levels of lysine (1.40%, 1,60% and 1.80%) and two levels of L-carnitine (0 and 1,000 ppm). Each treatment had 4 replications with 5 pigs per replicate. Pigs of $22{\pm}1$ days (5.9 kg of body weight) were grouped into a completely randomized block design. Treatments were 1) 1.4-Crt; 1.40% of lysine with 1,000 ppm of L-carnitine, 2) 1.4-N; 1.40% of lysine without L-carnitine, 3) 1.6-Crt; 1.60% of lysine with 1,000 ppm of L-carnitine, 4) 1.6-N; 1.60% of lysine without L-carnitine, 5) 1.8-Crt; 1.80% of lysine with 1,000 ppm of L-carnitine and 6) 1.8-N; 1.80% of lysine without L-carnitine. Growth performance was optimized in pigs fed 1.6% lysine regardless of carnitine addition. For the first 7 days of the experimental period, the best ADG and F/G were found in pigs within the 1.6-Crt group. Carnitine significantly improved (p<0.05) ADG of pigs when the lysine level in the diet was 1.6%. Only in the third week carnitine had a significant influence on growth performance of pigs. A lysine-sparing effect of L-carnitine was not detected in this study. The 1.6-Crt group showed the best proximate nutrient digestibility, and the crude fat and gross energy digestibility were higher when the L-carnitine was added in the diet. Lysine level significantly affected the digestibilities of DM (p<0.001), GE (p<0.001), CP (p<0.01) and C.fat (p<0.05). Carnitine also significantly improved digestibility of nutrients. Lysine level as well as carnitine level affected the amino acids digestibility, however, in 1.8% lysine diet carnitine did not influence on amino acids digestibility. Plasma carnitine content was significant higher (p<0.05) in pigs fed L-carnitine. This indicates the increased biological availability of carnitine within the body. L-carnitine supplementation tended to improve feed utilization during the third week (p<0.10) and during the entire period (p=0.10). Lysine level significantly affected feed utilization of pigs during the third week and entire period (p<0.05). As pigs grew, the lysine requirement was reduced.

• Clinical and Experimental Pediatrics
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• 제45권9호
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• pp.1083-1089
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• 2002

목 적 : 지속적으로 증가하는 소아 비만은 성인 비만으로 이행되기 쉽고 합병증으로 고혈압, 지방간, 동맥경화증이 동반될 수 있다. Carnitine은 장쇄 지방산이 미토콘드리아로 이동할 때 필요한 조효소로 지방산 대사에서 중요한 역할을 한다. 지방간을 가진 비만 소아에서 혈중 지방산과 carnitine 농도를 측정함으로써 L-carnitine을 임상적으로 비만 치료에 적용할 수 있는지를 알아보고자 본 연구를 실시하였다. 방 법 : 7-18세의 지방간으로 진단받은 비만아 9명과 정상 대조군 소아 10명을 대상으로 하였다. 혈장을 sodium borate를 섞어 원심분리 후 하층을 methylene chloride를 이용하여 계층 분리하였고, MSTFA와 acetonitrile을 넣고 유도체화 반응을 시켰다. GC-MS 자동 분석기로 혈청 지방산 fraction을 정량 분석하였고, carnitine(free, acyl, total)은 cycling technique을 이용하여 415 nm에서 정량 분석하였다. 결 과 : 혈중 총 지방산은 지방간이 동반된 비만아 군에서 대조군에 비해 유의하게 증가하였고 특히 장쇄 지방산(myristic acid, palmitoleic acid, palmitic acid, linoleic acid, oleic acid, stearic acid)이 의미 있게 증가되어 있었다. 총 carnitine과 유리 carnitine 농도가 비만아에서 정상아에 비해 유의하게 증가하였으나 acyl carnitine은 유의한 차이가 없었다. 결 론 : 지방간이 동반된 비만아에서 장쇄 지방산이 뚜렷이 증가되었으며, 비만아군에서 정상아에 비해 혈청 carnitine이 증가되어 있음을 알 수 있었다. 이것을 기초로 하여 비만아에서 L-carnitine 투여 후 지방산 대사의 변화에 대해 추후에 연구할 예정이다.

• Clinical and Experimental Pediatrics
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• 제45권9호
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• pp.1075-1082
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• 2002

목 적: L-carnitine은 carnitine acyltransferase 효소에 의해 장쇄(long chain)지방산을 세포질에서 미토콘드리아로 이동시킬 때 필요한 효소로 미토콘드리아 내로 이동된 장쇄 지방산은 ${\beta}$-산화를 거쳐 신체의 에너지원으로 사용된다. 비만 치료 방법의 하나로 L-carnitine을 투여하여 간과 근육세포의 산화를 증가시켜 혈청 지방을 감소시키려는 시도가 있으며, 실제로 L-carnitine이 혈청 지방산을 낮추는지를 알아보기 위해 본 연구를 실시하였다. 방 법: 250 g 내외의 Sprague Dawley 쥐를 두 군으로 나누어 실험하였다. A군은 정상 대조군, B군에서 L-carnitine을 200 mg/kg씩 매일 복강 내로 투여하였다. Hitachi 기기를 이용하여 총 콜레스테롤, 중성지방, 고분자량 콜레스테롤, 저분자량 콜레스테롤을 측정하였고, 혈청 C6-C18 지방산은 GC/MS 분석에 의해 1일, 1주, 2주에 측정하였다. Cycling 기법을 이용하여 총 carnitine, 유리 carnitine, 아실 carnitine을 정량 분석하였다. 결 과 : 1) 혈청 총 콜레스테롤, 고분자량 콜레스테롤, 저분자량 콜레스테롤은 두 군 사이에 유의한 차이가 없었으나, 중성지방은 1주일째에 A군은 $131.3{\pm}31.3mg/dL$인데 반하여 B군은 $90.0{\pm}7.0mg/dL$로 의미있는 감소를 보였다. 2) 혈청 총 지방산은 A군에 비해 B군에서 1주에만 약간의 감소를 보였으나 통계학적 유의성은 없었다. 1주일째 장쇄 지방산인 리놀레인 산(linoleic acid)이 B군에서 A군에 비해 유의하게 감소하였다. 3) L-carnitine투여 후 carnitine(total, free, acyl) 치는 1일째, 1주일째 및 2주일째에 모두 B군이 A군보다 유의하게 높았으나, 유리 carnitine 만이 투여 누적 용량에 따라서 유의한 증가를 보였다. 결 론 : L-carnitine 투여 후 1주일째에 혈중 중성 지방의 농도가 감소하였고, 리놀레인 산이 미토콘드리아 내로 이동함으로 혈중 농도의 감소를 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권2호
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• pp.237-242
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• 2001

Colostrum deprived, newborn pigs (N=12, $1.64{\pm}0.05kg$) were used to study the renal threshold of carnitine, and effects of emulsified medium-chain triglyceride (MCT, tri-8:0) feeding on kinetics of plasma carnitine and urinary carnitine excretion. An arterial catheter was inserted through an umbilical artery, and a bladder catheter was inserted via the urachus. Piglets were oro-gastrically gavaged with one of six carnitine levels (0, 60, 120, 180, 240, $480{\mu}mol/kg\;W^{0.75}$) with (+MCT) or without medium-chain triglycerides (-MCT) in 0.9% NaCl solution. Blood was sampled into heparinized tubes at 0, 1, 2, 4, 6, 8, 14, and 20 h after gavage, and urine was collected and pooled into 1 h or 2 h composite samples to determine free- and short-chain carnitine concentrations. Plasma from the 12 newborn piglets before gavage contained $10.6{\pm}1.2{\mu}mol/L$ free carnitine and $7.2{\pm}0.6{\mu}mol/L$ acid-soluble acyl carnitine. The renal threshold for carnitine was similar between the MCT and the +MCT group (42.6 13.1 and $46.4{\pm}2.0{\mu}mol/L$, respectively), but the correlation between plasma free carnitine and urinary excretion was altered. Plasma free carnitine linearly increased with increasing carnitine dosage (-MCT group, $R^2=0.95$, p<0.001; +MCT group, $R^2=0.91$, p<0.001), but was decreased by 50% when medium-chain triglycerides were fed. The peak in plasma free carnitine concentration was depressed by medium-chain triglycerides feeding also. Therefore, the plasma and urinary short-chain/free carnitine ratio of the +MCT group was increased by 100% and 40%, respectively (p<0.01). Feeding of medium-chain triglycerides may delay plasma carnitine elevation via altering the kinetics of absorption. Similarly, the plasma and urinary short-chain/free carnitine ratio were affected by interaction between medium-chain triglycerides and time (p<0.01). The present study suggests that an oral carnitine dose over $480{\mu}mol/kg\;W^{0.75}$ may be needed to reach the free carnitine renal threshold within a short period, especially when provided together with medium-chain triglyceride.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.601-605
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• 1998

For the resolution of L-carnitine from DL-carnitine, resting cells of Enterobacter sp. NH-104, which had a higher capacity of D-carnitine decomposition, were harvested at maximal specific activity of D-carnitine decomposition of 47.05 unit/mg cell. The cells were frozen at $-80^{\circ}C$ to assess functions as enzyme sources. Optimal concentration of cells and DL-carnitine were 17 g/$\ell \; and \; 20 g/\ell$, respectively, and reaction buffer was best at 75 mM of Tris. HCl. Optimal temperature and pH were $36^{\circ}C$ and 8.2, respectively. When the reaction at optimal conditions was carried out for 14 h, the optical purity was 98.21 %, and the quantity and yield of remaining L-carnitine were 4.432 g/$\ell$ and 44.32%, respectively.

• Preventive Nutrition and Food Science
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• 제3권3호
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• pp.251-255
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• 1998

Rat testis known to contain all of the enzymes required for carnitine biosynthesis also contains high concentration of calmodulin, a protein which may or may not contain trimethyllysine, the major substrate in carnitine biosynthesis. The purpose of this study was to investigate the levels of carnitine and the state of calmodulin N-methylation in rat testes, and to discuss the possibility of the involvement of calmodulin incarnitine biosynthesis. Nonesterified carnitine , acid soluble acyl carnitine, and acid insoluble acyl carnitine of ra tests were 273 nmole, 62nmole, and 4 nmole/g tissue, respectively. Total carnitine level was 339 nmole/g testes tissue. Calmodulin purified from rat tests was assayed for methylation potential using N-methyltransferase from the rat testes. Rat testes calmodulin showed no 3H-methyl incorporation indicating that the calmodulin was trimethylated already by endogenous calmodulin N-methyltransferase. Amino acid composition analysis revealed that the rat testes calmodulin containd one mole of trimethyllysine per mole of calmodulin. These data suggest that testes calmodulin could provide the trimethyllysine needed for the synthesis of carnitine in the rat tests.

• Journal of Nutrition and Health
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• 제36권7호
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• pp.720-728
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• 2003

This study was conducted to evaluate changes in plasma concentration and urinary excretion of carnitine, as well as plasma lipid level and fatty acid composition, caused by short term supplementation of carnitine in humans. Ten healthy male subjects (21.2 $\pm$ 0.5 years old) received oral carnitine supplementation (4 g/day) as tablets for two weeks. Fasting blood and random urine samples were collected from each subject both prior to and at the end of carnitine supplemention program. Following the 2 weeks of carnitine supplementation, plasma total carnitine (TCNE) concentration increased 20% (85.1 $\pm$ 7.4 vs 67.3 $\pm$ 9.1 $\mu$ mol/1, p> 0.05), while urinary excretion of total carnitine increased ten times compared to the value measured prior to the supplementation (3051 $\pm$ 692 vs 278 $\pm$ 90.1 $\mu$ mol/g creatinine, p < 0.01). Non-esterified carnitine (NEC) comprised from 71 to 88% of TCNE in plasma, and from 32 to 40% of TCNE excreted in the urine. Two weeks of carnitine supplementation in healthy adults significantly elevated plasma level of acid soluble acylcarnitine (ASAC) which is esterified mostly with short chain fatty acids (21.6 $\pm$ 1.6 $\mu$ mol/l) compared to the value measured prior to the supplementation (6.4 $\pm$ 0.8 $\mu$ mol/l) (p < 0.05). Carnitine supplementation significantly increased plasma HDL-cholesterol level (p < 0.05), and decreased the atherogenic index (p < 0.05), but failed to cause any significant change in plasma levels of total cholesterol, triglyceride, and free fatty acids. Plasma triglyceride and phospholipid fatty acid compositions were not significaly affected as well by the oral supplementation of carnitine in subjects with normal range of blood lipid levels.

• Asian-Australasian Journal of Animal Sciences
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• 제12권8호
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• pp.1263-1272
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• 1999

The effects of carnitine in diets with or without added fat (5% lard or soybean oil) were evaluated in 72 Large White ${\times}$ Landrace ${\times}$ Duroc pigs weaned at 35 days of age. Pigs were fed a 1.30% lysine corn-soybean basal diet+15% dried whey+4% fish meal with carnitine at 0 or 50 mg/kg and either 0% added fat, 5% soybean oil or 5% lard for 6 weeks in a $2{\times}3$ factorial trial (6 treatments, 3 pens per treatment, 4 pigs per pen). Addition of carnitine increased average daily gain (ADG) and average daily feed intake (ADFI) in the second two weeks of the six-week trial and overall, but had no significant effect on feed per gain (F/G). Lard alone depressed ADG (p<0.05) in the last two weeks of the trial and overall, but the ADG for pigs fed lard+carnitine was similar to the control. Lard reduced feed intake in the first two weeks of the trial (p<0.05). Carnitine reduced the percentage of pigs with poor (ADG<375 g/d) growth (15 vs 40%; p<0.05). The greater uniformity of growth was most evident in low-weaning-weight pigs in the second period (16 vs 62%, p<0.005). Addition of fat did not produce any positive effect on uniformity and had no interaction with carnitine on uniformity. Carnitine addition increased serum total carnitione and short-chain acyl-carnitine levels (p<0.05), but did not modify free carnitine levels. Serum carnitine levels were lower at weaning than at 14, 28, or 39 days after weaning (p<0.05). Carnitine increased serum protein levels on day 14 (p<0.05). Addition of fat in the form of soybean oil or lard did not improve piglet growth performance. Addition of 50 mg/kg of carnitine to the diet of weanling pigs enhanced postweaning performance.