Original ArticlesDietary Peptides Improve Wound Healing Following Surgery☆
Abstract
To determine if peptide-based enteral diets improve wound healing when compared to amino acid-based diets, a prospective randomized study was conducted using 38 male Sprague–Dawley rats. Following placement of a standardized abdominal wound, 20 animals were randomized to an isonitrogenous peptide-based (PEP) versus amino acid-based diet (AA) for 10 d. In addition, 18 animals were randomized to an amino acid-based diet supplemented with the peptide carnosine (CARN) or its constituent amino acids (Control). Diets were administered through small bowel feeding tubes. Wound bursting pressure was significantly higher in the PEP animals compared to the AA animals (179 ± 9 versus 138 ± 12 mmHg; P = 0.02). In addition, wound bursting pressure was significantly greater in the CARN animals compared to the Control animals (143 ± 10 versus 116 ± 8 mmHg; P = 0.005). Peptide-based enteral diets improve wound healing when compared to nonpeptide generating amino acid-based diets. We also conclude that the dietary peptide carnosine represents a dietary peptide that improves wound healing when administered as part of a complete enteral formula. This effect on wound healing may be clinically relevant because carnosine is not found in most enteral formulas.
Introduction
Unhealed wounds are a constant source of inflammatory mediators and a substrate for infection. As such, they prolong the recovery of injured patients and may lead to multiple organ failure and death. Therefore, a major goal of nutritional support of the injured patient is the improvement of wound healing. Numerous nutrients are known to be important for optimal wound healing and include total protein and calorie intake,1, 2, 3, 4, 5arginine,1, 6, 7zinc,1, 8ascorbic acid,1, 9, 10and vitamin A.1, 11, 12Early initiation of enteral nutrition following injury is also important for stimulating healing.[13]
Our laboratory has been studying the biogenic effects of dietary amines.[14]We have found that nitrogen utilization varies with the type of protein used to feed animals.15, 16We believe that peptides generated from dietary proteins during digestion play a role in optimizing growth and healing. These peptides may directly stimulate cells involved in the growing or healing process or may act indirectly by augmenting the production of growth factors. Our previous studies assessed nitrogen utilization from dietary peptides using animal growth rates.15, 16Growth rates were higher in animals receiving peptide-generating diets compared to amino acid-based diets.[15]
We now extend our previous results by assessing the biogenic effects of dietary peptides on wound healing. We tested the hypothesis that dietary peptides augment the healing of abdominal wounds when administered as part of a complete enteral nutrition program. We measured wound healing in animals randomized to a peptide- versus nonpeptide-generating diet (i.e., amino acid-based diet) and in animals in which the dietary peptide carnosine was added to an amino acid diet. Carnosine is a peptide that has been previously shown to augment wound healing following parenteral administration.17, 18
Access through your organization
Check access to the full text by signing in through your organization.Access through your organization
Section snippets
Materials and Methods
This protocol was approved by our institutional animal care and use committee and followed National Research Council guidelines for the care and use of laboratory animals. Healthy, well-nourished, male Sprague–Dawley rats (Harlan, Indianapolis, IN, USA) weighing 300–350 g were maintained on rat chow (Prolab Rodent Diet, Agway, Syracuse, NY, USA) prior to study. On the first day of study, animals were anesthetized with intramuscular ketamine hydrochloride and intraperitoneal sodium
Experiment 1
All animals received the same quantity of formula per day. Protein intake was similar between PEP and AA groups (Table I). However, caloric intake was slightly but significantly (P < 0.05) lower in the PEP group (because formulas were matched for nitrogen intake). Weight gain was significantly greater in AA than PEP animals (46 ± 4 g versus 19 ± 7 g over 10 d; P = 0.01). However, abdominal bursting pressure was significantly greater (P = 0.02) in the PEP group compared to the AA group (Fig. 1).
Discussion
The results of this study indicate that dietary peptides improve wound healing in rats. The first study compared two commercially available nutritional formulas that differed in the form of their protein. One contained amino acids (nonpeptide-generating diet) and the other contained peptides. However, these formulas also differed in their composition of amino acids, lipid, and carbohydrate. They were similar in their composition of minerals, trace elements, and vitamins. Both diets contained
References (26)
et al.
Wound healing and thymotropic effects of argininea pituitary mechanism of action
J Am Coll Nutr
(1983) PR Roberts
Wound healing NW Law et al.
The effect of parenteral nutrition on the healing of abdominal wall wounds and colonic anastomoses in protein-malnourished rats
Surgery
(1990) ME Young
Malnutrition and wound healing
Heart Lung
(1988) DA Haydock et al.
Impaired wound healing in surgical patients with varying degrees of malnutrition
JPEN
(1986) TT Irvin
Effects of malnutrition and hyperalimentation on wound healing
Surg Gynecol Obstet
(1978) A Barbul et al.
Arginine enhances wound healing and lymphocyte immune responses in humans
Surgery
(1990) WJ Pories et al.
Acceleration of healing with zinc sulfate
Ann Surg
(1967) MK Bartlett et al.
Vitamin C and wound healing. I. Experimental wounds in guinea pigs
N Engl J Med
(1942) MK Bartlett et al.
Vitamin C and wound healing. II. Ascorbic acid content and tensile strength of healing wounds in human beings
N Engl J Med
(1942) TK Hunt et al.
Effect of vitamin A on reversing the inhibitory effect of cortisone on healing of open wounds in animals and man
Ann Surg
(1969) J Weinzweig et al.
Supplemental vitamin A prevents the tumor-induced defect in wound healing
Ann Surg
(1990) GP Zaloga et al.
Immediate postoperative enteral feeding decreases weight loss and improves wound healing after abdominal surgery in rats
Crit Care Med
(1992)
Cited by (53)
Chapter 3 Carnosine and Its Possible Roles in Nutrition and Health
2009, Advances in Food and Nutrition Research
One problematic aspect of the aged organism is slower wound healing. There is evidence that carnosine can have beneficial effects here (Roberts et al., 1998). When carnosine is complexed with zinc to form “polaprezinc,” it behaves as an antiulcer drug which also possesses wound‐healing activity (Nagai et al., 1986). View all citing articles on Scopus
☆
Supported by the Department of Anesthesiology, Bowman Gray School of Medicine, Winston–Salem, NC, USA.View full text
Copyright © 1998 Elsevier Science Inc. All rights reserved.