The effects of age and various fat/carbohydrate caloric ratios on nitrogen retention and wound healing in rats.

Abstract

Recent reports have indicated a possible age-related component to the ability of various species to utilize either fat or carbohydrate as their preferential energy source. These studies have demonstrated that infant rats given a high-fat diet (50% fat, 35% carbohydrate, 15% protein) retain a significantly higher amount of nitrogen than do infant rats on a high-carbohydrate diet (82% carbohydrate, 3% fat, 15% protein). Conversely, adult rats maintain a higher positive nitrogen balance when given the high-carbohydrate diet. In light of these studies, and our interest in factors that contribute to wound healing in the surgical patient, we investigated the effects of low-, medium-, and high-fat enteral diets on wound healing and nitrogen balance in surgically stressed rats of various ages. Weanling (45 g) and young adult (175 g) male Sprague-Dawley rats (n = 16 per age group) were housed individually in metabolic cages. All animals had Impra vascular-graft wound cylinders placed subcutaneously in the dorsal midline and were placed in four dietary groups: high fat (50% kcal), medium fat (30% kcal), low fat (2.5% kcal), and chow (Purina Standard Laboratory Rodent Chow, 17% kcal as fat). All test diets were isonitrogenous (3.1 g nitrogen/1,000 kcal) and isocaloric for each age group. Animals in each age group were pair-fed (35 kcal/d, weanlings; 60 kcal/d, young adults) for 10 days and then euthanized. Wound cylinders were removed and analyzed for collagen content.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: P J Hennessey, J G Nirgiotis, R J Andrassy
• Journal: Journal of pediatric surgery (J Pediatr Surg) Vol. 26 Issue 4 Pg. 367-72; discussion 372-3 (Apr 1991) ISSN: 0022-3468 [Print] United States
• PMID: 2056395 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Blood Proteins
• Dietary Carbohydrates
• Dietary Fats
• Serum Albumin
• Collagen
• Nitrogen

Topics

• Aging
• Analysis of Variance
• Animals
• Blood Proteins (analysis)
• Collagen (analysis)
• Dietary Carbohydrates (metabolism)
• Dietary Fats (metabolism)
• Male
• Nitrogen (metabolism)
• Rats
• Rats, Inbred Strains
• Serum Albumin (analysis)
• Wound Healing (physiology)