Effects of L-NG-Monomethyl-Arginine on Apoptosis of Articular Chondrocytes

Abstract

We aimed to investigate the effects of L-NG-monomethyl-arginine on the apoptosis of articular chondrocytes. 30 rabbits were randomly divided into six groups (n=5). The pathological changes were detected by Hematoxylin and Eosin staining. The expression levels of synovial fluid and serum nitric oxide were measured. The apoptosis of chondrocytes was tested using the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. The expression levels of reconstituted B-cell lymphoma-2 and human B-cell lymphoma-2 associated X protein in cartilage tissues were detected by immunohistochemical assay. The Mankin score of the model group was significantly higher than that of the control group (p<0.01). The scores significantly decreased in L-NG-monomethyl-arginine treatment groups (p<0.05). The expression levels of B-cell lymphoma-2 associated X protein, apoptosis rate and index of chondrocytes, and those of synovial fluid and serum nitric oxide were markedly higher in the model group than those in the control group (p<0.01). However, the expression levels of B-cell lymphoma-2 in model and control groups were similar (p>0.05). With increasing L-NG-monomethyl-arginine treatment dose, the expression level of B-cell lymphoma-2 and B-cell lymphoma-2/B-cell lymphoma-2 associated X protein ratio were significantly elevated (p<0.05). L-NG-monomethyl-arginine reduced the expressions of synovial fluid and serum nitric oxide, and raised B-cell lymphoma-2/B-cell lymphoma-2 associated X protein ratio, thereby inhibiting chondrocyte apoptosis.