title: [Assay of carnitine in plasma and urine of healthy adults].
abstract: OBJECTIVE
  To determine the levels of carnitine in plasma and daily excretion of carnitine in urine of healthy adults so as to provide the reference standard for studying the changes of carnitine in patients.
  
  
  METHODS
  Carnitine in plasma and urine was assayed with high performance liquid chromatography (HPLC). The levels of total carnitine (TC), free carnitine (FC) and acetyl-carnitine (AC) in fasting plasma and the daily excretion of TC, FC and AC in urine were assayed in 40 healthy adults (20 men and 20 women) with standard diet.
  
  
  RESULTS
  Good linearity (r 2 > or = 0.999) was observed in assaying TC, FC and AC. The relative standard deviation (RSD) was lower than 9.1% and bias lower than 5.6%. It was showed that the plasmatic levels of TC, FC and AC in healthy men [(53.1 +/- 8.5), (41.2 +/- 6.1), (6.2 +/- 0.6) mumol/L] were significantly higher than those in healthy women [(45.4 +/- 5.6), (35.2 +/- 4.9), (5.7 +/- 0.7) mumol/L] (P = 0.002, 0.002, 0.035). The daily urinary excretion of TC, FC and AC in healthy men [(386.1 +/- 22.9), (180.5 +/- 31.8), (33.8 +/- 3.3) mumol] were also significantly higher than those in healthy women [(240.1 +/- 35.6), (112.7 +/- 22.6), (29.3 +/- 4.3) mumol] (P < 0.0005, < 0.0005, < 0.0005) when the adults were given standard diet. Both the plasmatic levels and the daily urinary excretion of TC, FC and AC were of significantly positive correlation with lean body mass (LBM) (r = 0.501-0.856). The (TC-FC)/FC ratios in plasma were 0.29 +/- 0.05 for male and 0.29 +/- 0.04 for female.
  
  
  CONCLUSIONS
  Good precision and accuracy were observed in assaying carnitine with HPLC. After standard diet, both the level of carnitine in fasting plasma and the daily urinary carnitine excretion of healthy adults were positively correlated with LBM.
authors.affiliation: Department of Surgery, PUMC Hospital, CAMS, PUMC, Beijing 100730, China. niuyj2000@hotmail.com
authors.forename: Yu-jian
authors.initials: YJ
authors.lastname: Niu
authors.forename: Zhu-ming
authors.initials: ZM
authors.lastname: Jiang
authors.forename: Hong
authors.initials: H
authors.lastname: Shu
authors.forename: Chun-feng
authors.initials: CF
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Guo-xiang
authors.initials: GX
authors.lastname: Yao
authors.forename: Ji
authors.initials: J
authors.lastname: Jiang
authors.forename: Jing-quan
authors.initials: JQ
authors.lastname: Li
authors.forename: A
authors.initials: A
authors.lastname: Longo
mesh_terms: D000108:Acetylcarnitine / Q000097:blood / Q000652:urine; D000328:Adult; D002331:Carnitine / Q000097:blood* / Q000652:urine*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D012737:Sex Factors
chemical_list: D000108:Acetylcarnitine; D002331:Carnitine