Knodell R G
Gastroenterology Division, Baltimore Veterans Administration Medical Center, Maryland.
JPEN J Parenter Enteral Nutr. 1990 Jan-Feb;14(1):34-8. doi: 10.1177/014860719001400134.
Significant compositional differences in protein and lipid content are present in currently available enteral nutrition preparations. Since variations in dietary protein and/or lipid have previously been shown to produce alterations in liver and gut drug metabolism, effects of five commonly used enteral nutrition regimens on several drug metabolic parameters were assessed in rats. Study formulations included: 1) Vivonex: low protein -no lipid; 2) High Protein Vivonex: normal protein -no lipid; 3) Vital: normal protein -normal lipid; 4) Sustacal: high protein -high lipid; 5) Isocal: normal protein -high lipid. Hepatic and intestinal microsomes were prepared after a continuous 7-day intragastric infusion of one of the formulations, and measurements of cytochrome P-450 content and assays of drug metabolizing activity were performed. No differences in intestinal microsomal cytochrome P-450 content or meperidine demethylase activity were seen among the various alimentation groups. However, significantly decreased amounts of cytochrome P-450 and reduced meperidine demethylase and pentobarbital hydroxylase activity were present in hepatic microsomes of animals receiving the lipid-poor Vivonex and High Nitrogen Vivonex preparations compared to the other alimentation groups. These data suggest that the composition of enteral nutrition formulations may significantly impact on hepatic function and specifically that the presence of lipid in such preparations may be important for maintaining normal levels of hepatic drug metabolism.
目前市面上的肠内营养制剂在蛋白质和脂质含量上存在显著的成分差异。由于先前已表明膳食蛋白质和/或脂质的变化会导致肝脏和肠道药物代谢的改变，因此在大鼠中评估了五种常用肠内营养方案对几种药物代谢参数的影响。研究配方包括：1）Vivonex：低蛋白 - 无脂质；2）高蛋白Vivonex：正常蛋白 - 无脂质；3）Vital：正常蛋白 - 正常脂质；4）Sustacal：高蛋白 - 高脂；5）Isocal：正常蛋白 - 高脂。在连续7天胃内输注其中一种配方后制备肝和肠微粒体，并进行细胞色素P-450含量的测定和药物代谢活性的检测。在不同营养组之间未观察到肠微粒体细胞色素P-450含量或哌替啶脱甲基酶活性的差异。然而，与其他营养组相比，接受低脂质的Vivonex和高氮Vivonex制剂的动物肝微粒体中细胞色素P-450的量显著减少，哌替啶脱甲基酶和戊巴比妥羟化酶活性降低。这些数据表明，肠内营养制剂的成分可能会对肝功能产生显著影响，特别是这些制剂中脂质的存在对于维持肝脏药物代谢的正常水平可能很重要。
