<i>L</i>-Arginine: A Unique Amino Acid for Improving Depressed Wound Immune Function following Hemorrhage

Abstract

Objective: To determine whether L-arginine has any salutary effects on wound immune cell function following trauma-hemorrhage. Background: Depressed wound immune function contributes to an increased incidence of wound infections following hemorrhage. Although administration of L-arginine has been shown to restore depressed cell-mediated immune responses following hemorrhage potentially by maintaining organ blood flow, it remains unknown whether L-arginine has any salutary effects on the depressed local immune response at the wound site. Methods: Male mice were subjected to a midline laparotomy and polyvinyl sponges were implanted subcutaneously in the abdominal wound prior to hemorrhage (35 ± 5 mm Hg for 90 min and resuscitation) or sham operation. During resuscitation mice received 300 mg/kg body weight L-arginine or saline (vehicle). Sponges were harvested 24 h thereafter, wound fluid collected and wound immune cells cultured for 24 h in the presence of LPS. Pro- (IL-1β, IL-6) and anti-inflammatory (IL-10) cytokines were determined in the supernatants and the wound fluid. In addition, wounds were stained for IL-6 immunohistochemically. In a separate set of animals, skin and muscle blood flow was determined by microspheres. Results: The capacity of wound immune cells to release IL-1β and IL-6 in vitro was significantly depressed in hemorrhaged mice receiving vehicle. Administration of L-arginine, however, improved wound immune cell function. In contrast, in vivo the increased IL-6 release at the wound site was decreased in L-arginine-treated mice following hemorrhage. Moreover, IL-10 levels were significantly increased in the wound fluid in hemorrhaged animals receiving L-arginine compared to vehicle-treated mice. In addition, the depressed skin and muscle blood flow after hemorrhage was restored by L-arginine. Conclusions: Thus, L-arginine might improve local wound cell function by decreasing the inflammatory response at the wound site. Since L-arginine protected wound immune cell function this amino acid might represent a novel and useful adjunct to fluid resuscitation for decreasing wound complications following hemorrhage.

Arginase, Prostaglandins, and Myeloid-Derived Suppressor Cells in Renal Cell Carcinoma

“…Arginase I metabolizes arginine to ornithine. Patients with severe trauma, who also have an increased arginase activity in PBMC, have a rapid decline in serum arginine levels (9,10). Mean plasma levels of arginine were significantly decreased in the 15 patients studied (28.48 F 32.51 Amol/L) compared with controls (90.0 F 15.56 Amol/L) (Fig.…”

Effects of Arginine Supplementation on Organ Development, Egg Quality, Serum Biochemical parameters, and Immune Status of Laying Hens

“…Arginine supplementation stimulates the functional activities of different cell types, including natural-killer cells, and the systemic immune response against IBDV in chickens and anti-BSA (bovine serum albumin) IgM levels in lying hens (Deng et al, 2005). In addition, arginine may improve local wound healing by decreasing the inflammatory response at the wound site (Angele et al, 2002).…”

Depletion ofL-arginine induces autophagy as a cytoprotective response to endoplasmic reticulum stress in human T lymphocytes

“…However, no apoptotic response was observed nitric oxide synthase to produce urea and L-ornithine, and nitric oxide and L-citrulline, respectively. 1 L-Arg levels are profoundly reduced in cancer patients, 2 following liver transplantation, 3 or in severe trauma, 4 correlating with increased arginase I serum levels. L-Arg deficiency results in decreased T-cell proliferation and impaired T-cell function.…”