氰化物中毒对肝脏硫氰酸酶动力学的影响。

The effect of cyanide intoxication on hepatic rhodanese kinetics.

Buzaleh A M, Vazquez E S, Batlle A M

Centro de Investigaciones sobre Porfirinas y Porfirias, CONICET, Facultad de Ciencias Exactas y Naturales, University of Buenos Aires, Argentine.

Gen Pharmacol. 1990;21(2):219-22. doi: 10.1016/0306-3623(90)90904-z.

Abstract

Results of studies on the kinetics of hepatic rhodanese and the effects of S-adenosyl-L-methionine (SAM) on these kinetic parameters in cyanide-treated and non-treated mice are reported here. 2. The enzyme exhibited typical Michaelis-Menten behaviour with cyanide inhibition at concentrations higher than 50 mM. Km values of 4.74 and 0.85 mM were obtained for thiosulphate and cyanide, respectively, in control mice. 3. These results stress the biological importance of the rhodanese reaction for cyanide detoxification. 4. Km values were not significantly modified when the animals were intoxicated with a lethal (20 mg/kg) or a non-lethal (4 mg/kg) dose of cyanide. 5. SAM treatment either in control or in cyanide-poisoned animals doubled the Km's for cyanide.

摘要

本文报道了关于肝脏硫氰酸酶动力学的研究结果，以及S-腺苷-L-蛋氨酸（SAM）对氰化物处理和未处理小鼠这些动力学参数的影响。2. 该酶表现出典型的米氏行为，在浓度高于50 mM时受到氰化物抑制。在对照小鼠中，硫代硫酸盐和氰化物的Km值分别为4.74和0.85 mM。3. 这些结果强调了硫氰酸酶反应对氰化物解毒的生物学重要性。4. 当动物用致死剂量（20 mg/kg）或非致死剂量（4 mg/kg）的氰化物中毒时，Km值没有显著改变。5. 在对照动物或氰化物中毒动物中进行SAM处理，使氰化物的Km值增加了一倍。