Arginine stimulates wound healing and immune function in elderly human beings.

Abstract

This prospective randomized trial evaluated the effect of oral supplements of arginine aspartate on wound healing and immune responses in healthy elderly (over 65 years old) volunteers. This laboratory previously demonstrated that arginine supplementation enhances wound‐breaking strength, reparative collagen synthesis, and T‐cell‐mediated immune function in healthy animals and human beings,1,2 whereas immune suppression associated with trauma is abrogated.3 Thirty subjects received daily supplements of 30 g of arginine aspartate (17 g of free arginine) and 15 individuals received placebo syrup for a 14‐day course. Wound healing was evaluated by two methods: (1) fibroplasia was measured by using subcutaneously implanted polytetrafluoroethylene catheters for the determination of collagen deposition, total protein, and DNA content, and (2) rate of wound epithelialization was assessed by using a standard partial‐thickness wound. Lymphocyte blastogenesis was measured in a microculture system by using mitogenic stimulation with standard mitogens as well as alloantigens in a mixed lymphocyte response with stimulator cells collected from pooled healthy human donors. Serum insulin‐like growth factor‐1 (IGF‐1) was determined by radioimmunoassay.Arginine supplementation enhanced wound fibroplasia as evidenced by an increase in the amount of collagen deposition and total protein content. However, DNA content and time to complete epithelialization were equivalent in both groups. The blastogenic response of peripheral blood lymphocytes to all mitogens and alloantigens was significantly enhanced in the arginine‐supplemented group. Serum IGF‐1 levels were also significantly elevated in the arginine group.