[Studies on DNA single strand breaks induced by sodium nitroprusside-nitric oxide donor].

OBJECTIVE: To study the effect of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on DNA single strand breaks (SSBs). METHODS: A modified method was used to isolate and prepare the single cell suspension from the organs of mice. Alkaline single-cell gel electrophoresis (SCGE) was performed to examine DNA damage of the cells treated by SNP in vivo and in vitro. RESULTS: Treatment with 0.5 - 2.0 micromol/ml of SNP with S(9) for 1 h induced a concentration-dependent increase in DNA SSBs in g12 cells. Significant increase in DNA migration and comet frequency in the spleen, thymus and peritoneal macrophage were induced after intraperitoneal injection of SNP at a dose of 0.67 - 6.0 mg/kg. No obvious increase in DNA single strand breaks was observed in the liver, kidney and lung of the mice with same treatment. CONCLUSION: DNA SSBs could be induced by NO in some cells in vivo and in vitro. There was difference in sensitivity of various organs in the mice to NO. Cells of spleen and thymus and macrophage may be the important target cells of NO.