Brinson R R, Pitts V L, Taylor A E
Department of Physiology, University of South Alabama College of Medicine, Mobile.
Crit Care Med. 1989 Jul;17(7):657-60. doi: 10.1097/00003246-198907000-00012.
Previous studies have confirmed the improved tolerance of a peptide enteral compared to standard enteral alimentation in hypoalbuminemic, critically ill patients. Animal studies, including hypoproteinemic, volume-expanded rats, demonstrated that the protein hydrolysate of a peptide enteral formula was responsible for the enhanced absorption. The purpose of this study was to determine whether the composition of small MW peptides (protein hydrolysate) in two commercially available peptide enteral formulas would affect the rate of intestinal absorption and albumin clearance in intact jejunal loops before and during hypoproteinemia induced by iv infusion of Tyrode's solution in Sprague-Dawley rats. Net transmucosal water movement was calculated using a volume recovery method; albumin clearance was calculated using iv radiolabeled albumin. We studied three groups of animals during luminal perfusion with either Tyrode's solution, diet A containing 21% peptides, or diet B containing 56% peptides. When compared to luminal perfusion with Tyrode's solution (control animals), both diets significantly enhanced net transmucosal water absorption before volume expansion (p less than .05). With the induction of hypoproteinemia, diet B continued to stimulate water absorption when compared to control animals (p less than .01). Luminal perfusion with diet A failed to attenuate net water secretion induced by hypoproteinemia. Capillary and mucosal albumin clearance was similar for all groups studied. These findings suggest the percentage of small MW peptides may affect the rate of intestinal absorption in patients with acute kwashiorkor-like hypoalbuminemia.
先前的研究已证实，与标准肠内营养相比，肽类肠内营养在低蛋白血症的危重症患者中耐受性更佳。动物研究，包括低蛋白血症、血容量增加的大鼠实验，表明肽类肠内营养配方中的蛋白质水解产物是吸收增强的原因。本研究的目的是确定两种市售肽类肠内营养配方中小分子量肽（蛋白质水解产物）的组成是否会影响在Sprague-Dawley大鼠静脉输注泰罗德溶液诱导低蛋白血症之前及期间，完整空肠袢的肠道吸收速率和白蛋白清除率。采用容积恢复法计算跨黏膜净水分移动；使用静脉注射放射性标记白蛋白计算白蛋白清除率。我们在三组动物的肠腔灌注期间进行了研究，分别灌注泰罗德溶液、含21%肽的饮食A或含56%肽的饮食B。与用泰罗德溶液进行肠腔灌注（对照动物）相比，两种饮食在血容量增加前均显著增强了跨黏膜净水分吸收（p<0.05）。诱导低蛋白血症后，与对照动物相比，饮食B继续刺激水分吸收（p<0.01）。用饮食A进行肠腔灌注未能减弱低蛋白血症诱导的净水分分泌。所有研究组的毛细血管和黏膜白蛋白清除率相似。这些发现表明，小分子量肽的百分比可能会影响急性夸希奥科样低蛋白血症患者的肠道吸收速率。
