Lundquist P, Rosling H, Sörbo B
Department of Clinical Chemistry, Linköping University, Uppsala, Sweden.
Arch Toxicol. 1988;61(4):270-4. doi: 10.1007/BF00364849.
The excretion of hydrogen cyanide in breath and blood concentrations of cyanide were measured in eight normal subjects. There was no correlation between breath and blood levels of cyanide. Furthermore, breath cyanide concentrations calculated from blood values were much lower than measured values, which suggested a local production of hydrogen cyanide in the oropharynx. When saliva was incubated at 37 degrees C hydrogen cyanide was formed in the presence of air but not in a nitrogen atmosphere. No hydrogen cyanide was formed with boiled saliva and the production of hydrogen cyanide by native saliva was inhibited by catalase and by 6-n-propyl-thiouracil. Centrifugation of saliva resulted in a supernatant and a sediment, which were both required for the formation of hydrogen cyanide. Dialysis of the supernatant abolished its cyanide forming ability, which could be restored by addition of thiocyanate. We conclude that most of the hydrogen cyanide found in breath from normal human beings originates from oxidation of thiocyanate by salivary peroxidase in the oropharynx. As a consequence measurements of breath hydrogen cyanide can only be used to detect heavy exposure to cyanide.
对8名正常受试者的呼出气体中氰化氢的排泄情况以及血液中氰化物的浓度进行了测量。呼出气体中的氰化物水平与血液中的氰化物水平之间没有相关性。此外，根据血液值计算出的呼出气体氰化物浓度远低于测量值，这表明口咽部位存在氰化氢的局部生成。当唾液在37℃下孵育时，在有空气存在的情况下会生成氰化氢，但在氮气环境中则不会。煮沸的唾液不会生成氰化氢，天然唾液生成氰化氢的过程会受到过氧化氢酶和6-正丙基硫氧嘧啶的抑制。对唾液进行离心会得到上清液和沉淀物，二者对于氰化氢的生成都是必需的。对上清液进行透析会使其失去生成氰化物的能力，通过添加硫氰酸盐可以恢复这种能力。我们得出结论，正常人体呼出气体中发现的大部分氰化氢源自口咽部位唾液过氧化物酶对硫氰酸盐的氧化。因此，呼出气体中氰化氢的测量仅可用于检测重度氰化物暴露情况。
