title: L-Arginine enhances cell proliferation and reduces apoptosis in human endometrial RL95-2 cells.
abstract: BACKGROUND
  L-arginine is considered to be one of the most versatile amino acids due to the fact that it serves as a precursor for many important molecules in cellular physiology. When supplemented in the diet, L-arginine can increase the number of implantation sites in mice and rats, suggesting an effect at the level of the endometrium. To this end, this study determined the effect that L-arginine has on apoptosis and cell proliferation in human endometrial RL95-2 cells.
  
  
  RESULTS
  L-arginine at physiological (200 micromol/L) and supra-physiological (800 micromol/L) concentrations increased cell proliferation at days 2 and 4 post-treatment with a dose-dependent effect being observed on day 2. Additionally, inhibition of nitric oxide (NO) synthase and arginase, which are responsible for the conversion of L-arginine to NO and polyamines, respectively, reduced the proliferative effect of L-arginine. L-arginine also decreased the proportion of cells with TUNEL positive nuclei and increased the ratio of cells with healthy mitochondria compared to cells with a disrupted mitochondrial membrane potential, indicating that L-arginine prevents mitochondrial mediated apoptosis in endometrial RL95-2 cells. Furthermore, exposure to L-arginine did not affect total BAD protein expression; however, L-arginine increased the abundance of phosphorylated BAD protein.
  
  
  CONCLUSIONS
  In summary, L-arginine added to the culture media at physiological (200 micromol/L) and supraphysiological concentrations (800 micromol/L) enhanced endometrial RL95-2 cell proliferation through mechanisms mediated by NO and polyamine biosynthesis. In addition, L-arginine reduced endometrial RL95-2 mitochondrial mediated apoptosis through increased phosphorylation of BAD protein.
authors: Department of Pathobiology and Population Medicine, Mississippi State University, Mississippi State, MS, USA. jmg211@msstate.edu
authors: Jonathan M
authors: JM
authors: Greene
authors: Jean M
authors: JM
authors: Feugang
authors: Kathryn E
authors: KE
authors: Pfeiffer
authors: John V
authors: JV
authors: Stokes
authors: Susan D
authors: SD
authors: Bowers
authors: Peter L
authors: PL
authors: Ryan
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D001120:Arginine / Q000502:physiology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004717:Endometrium / Q000166:cytology / Q000473:pathology / Q000502:physiology*; D005260:Female; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000502:physiology
chemical_list: D001120:Arginine