Nakamura S, Shin T, Hirokata Y, Shigematsu A
Br J Anaesth. 1977 Dec;49(12):1239-44. doi: 10.1093/bja/49.12.1239.
The influence of sodium nitroprusside (SNP) on mitochondrial respiration was examined in rat liver mitochondria. The addition of SNP 1 mmol litre-1 during state 3 respiration inhibited the oxygen uptake by 63.4%. A mixture of SNP 1 mmol litre-1 and glutathione (GSH) 1 mmol litre-1 inhibited the oxygen uptake more markedly (by 75.9%). The cyanide concentrations were 0.01 mmol litre-1 with SNP alone and 0.15 mmol litre-1 with the mixture of SNP and GSH. Cyanide production from SNP in the presence of various reducing agents was studied in potassium phosphate 0.1 mol litre-1 buffer solution (pH 7.4) incubated at 37 degrees C. Cyanide was liberated markedly from SNP in the presence of GSH or ascorbate. Less cyanide was produced in the presence of NADH or NADPH. The rate of production of cyanide was dependent entirely upon the concentration of each reducing agent added. No cyanide was liberated when sodium dithionite or the oxidized forms of GSH, NAD or NADP were used. It was concluded that SNP is degradated to cyanide by a hydrogen donor and that the cyanide liberated in this manner inhibits the cytochrome oxidase activity of mitochondria in vivo.
在大鼠肝线粒体中研究了硝普钠（SNP）对线粒体呼吸的影响。在状态3呼吸期间添加1 mmol/L的SNP可使氧摄取量降低63.4%。1 mmol/L的SNP与1 mmol/L的谷胱甘肽（GSH）的混合物对氧摄取的抑制作用更明显（降低75.9%）。单独使用SNP时氰化物浓度为0.01 mmol/L，SNP与GSH混合物时为0.15 mmol/L。在37℃孵育的0.1 mol/L磷酸钾缓冲溶液（pH 7.4）中，研究了在各种还原剂存在下SNP产生氰化物的情况。在GSH或抗坏血酸存在下，SNP可明显释放出氰化物。在NADH或NADPH存在下产生的氰化物较少。氰化物的产生速率完全取决于所添加的每种还原剂的浓度。使用连二亚硫酸钠或GSH、NAD或NADP的氧化形式时不会释放出氰化物。得出的结论是，SNP被氢供体降解为氰化物，并且以这种方式释放的氰化物在体内抑制线粒体的细胞色素氧化酶活性。
