objectives: previously we showed, low concentration and short time treatment with sodium nitroprusside (SNP) as a nitic oxide (NO) donor caused no harm to rat bone marrow mesenchymal stem cells(MSCs). This study was conducted to characterized the impact of NO on MSCs differentiation. Materials and Methods: MSCs were treated with 100 uMand 1000uM of SNP for 1 hour in every 48 Hours with osteogenic media. After 5, 10 and 21 days the viability and the level of mieralization was determined using MTT assay and alizarin red respectively. nuclear diameter and cytoplasm area of the cells were studied with the help of fluorescent dye. concentration of calcium and activity of ALT, AST, LDH and ALP were evaluated with the help of commercial kits. Results: SNP with concentration of 1000uM revealed to be toxic but the 100uM concentration did not show decrease of viability until the day 15. the low concentration of SNP increased the matrix deposition as well as activity of ALP, LDH and AST. In addition metabolic activity of the cell has changed from aerobic to anaerobic. Conclusiion: we recommend more investigation, but it may be announced that the prescription of low concentration of SNP might be use ful in promotion of bone repair.
