Tanphaichitr V, Lerdvuthisopon N
JPEN J Parenter Enteral Nutr. 1981 Nov-Dec;5(6):505-9. doi: 10.1177/0148607181005006505.
Urinary free and total carnitine excretions were measured in 41 normal adults and seven surgical patients on fat-free total parenteral nutrition for 8 to 45 days. The means (+/-SEM) of urinary free and total carnitine excretion in normal adults were 162 +/- 19 and 328 +/- 28 micrometers/days, respectively. All of the patients exhibited protein-calorie malnutrition with a mean carnitine intake of 11.6 +/- 1.5 micrometers/day. Under this stringent carnitine economy with the adequate supply of lysine and methionine, urinary total carnitine excretion significantly reduced to 127 to 162 micrometers/day. This probably reflects the carnitine biosynthetic rate. However, during the periods of operation and/or infection, urinary total carnitine excretion significantly increased 2- to 7-fold that of normal levels. Significant positive correlation was found between the two forms of urinary carnitine and total nitrogen excretions. Serum free and total carnitine levels in patients were significantly higher than normal adults. Such findings can be explained by the endocrine responses to the stress phenomenon and indicate a catabolic response of skeletal muscle in which most of the body carnitine resides. This can impair their carnitine status.
对41名正常成年人以及7名接受无脂全胃肠外营养8至45天的外科手术患者的尿游离肉碱和总肉碱排泄量进行了测定。正常成年人尿游离肉碱和总肉碱排泄量的均值（±标准误）分别为162±19和328±28微摩尔/天。所有患者均表现出蛋白质 - 热量营养不良，平均肉碱摄入量为11.6±1.5微摩尔/天。在这种严格的肉碱代谢状态下，赖氨酸和蛋氨酸供应充足，尿总肉碱排泄量显著降至127至162微摩尔/天。这可能反映了肉碱的生物合成速率。然而，在手术和/或感染期间，尿总肉碱排泄量显著增加，比正常水平高2至7倍。发现两种形式的尿肉碱与总氮排泄量之间存在显著正相关。患者血清游离肉碱和总肉碱水平显著高于正常成年人。这些发现可以通过对应激现象的内分泌反应来解释，表明骨骼肌存在分解代谢反应，而身体大部分肉碱都存在于骨骼肌中。这可能会损害他们的肉碱状态。
