Monooxygenase System and NO Metabolism in Liver Microsomes of Rats with Toxic Hepatitis and the Effect of Sesquiterpene Lactones

2021 ◽  
Vol 172 (2) ◽  
pp. 133-136
Author(s):  
N. V. Tursunova ◽  
V. N. Syrov ◽  
Z. A. Khushbaktova ◽  
Yu. V. Tornuev ◽  
M. G. Klinnikova
2000 ◽  
Vol 55 (11-12) ◽  
pp. 915-922 ◽  
Author(s):  
René Roser ◽  
Helmut Thomas

A highly sensitive fluorometric assay for the determination of monooxygenase activity in liver microsomes is described. The assay is based on the use of 3-chloro-7-methoxy-4-methylcoumarin which is demethylated to 3-chloro-7-hydroxy-4-methylcoumarin. The rate of formation of 3-chloro-7-hydroxy-4-methylcoumarin was recorded as an increase of fluorescence (λA = 380 nm, λF = 480 nm ) with time. When 3-chloro-7-methoxy-4-methylcoumarin was incubated in the presence of MgCl2and NADPH with rat liver microsomes, a continuous increase of the fluorescence could be measured. The reaction proceeded linearly for about 10 min and at least up to a concentration of 0.1 mg/ml of microsomal protein. Besides 3-chloro-7-hydroxy-4-methylcoumarin a hydroxylated derivative of the substrate was formed as a second metabolite during the incubation. Using an excitation wavelength of 480 nm and a fluorescence/em ission w avelength of 480 nm, the fluorescence of this substance (λA = 338 nm, λF = 422 nm ) amounted only to about 1% of the fluorescence of the main product. The use of 3-chloro-7-methoxy-4-methylcoumarin as substrate enables the fluorometric determination of the O-dealkylation activity of a cytochrom e P450-dependent monooxygenase system in rat liver which is inducible by phenobarbital but not by 3-methylcholanthrene.


Life Sciences ◽  
1970 ◽  
Vol 9 (20) ◽  
pp. 1189-1200 ◽  
Author(s):  
S.J. Yaffe ◽  
A. Rane ◽  
F. Sjöqvist ◽  
L.-O. Boréus ◽  
S. Orrenius

1987 ◽  
Vol 36 (7) ◽  
pp. 1053-1057 ◽  
Author(s):  
Tohru Horie ◽  
Mitsukazu Kitada ◽  
Yoshio Tanabe ◽  
Yoshio Kanakubo

1987 ◽  
Vol 36 (21) ◽  
pp. 3613-3619 ◽  
Author(s):  
C.Murray Ardies ◽  
Jerome M. Lasker ◽  
Charles S. Lieber

Author(s):  
I. Yu. Bagmut ◽  
I. L. Kolisnyk

Summary. The pathogenesis of fluoride intoxication at the molecular, cellular and functional levels has not been sufficiently studied. There are very few modern data on these issues, so they are contradictory, since the effects of this trace element are multifaceted and cannot be characterized unambiguously. The aim of the study – to learn the state of the monooxygenase system of rat hepatocytes under conditions of the formation of fluoride intoxication. Materials and Methods. In the experiment, we used 30 sexually mature rats (N=30) of the Wistar population weighing 200–210 g for 1.5 months. Sodium fluoride solution was administered orally at doses of 1/10 DL50, which was 20 mg/kg of animal body weight. Results. The results of experiments on the study of oxygen consumption by rat liver microsomes under fluoride intoxication indicated that the rate of endogenous respiration of microsomes, the rate of NADPH oxidation, the rate of NADH oxidation in the presence of EDTA, and the rate of lipid peroxidation increase under the influence of fluorides. Sodium fluoride stimulated an increase in all parameters of microsomal oxidation, except for cytochrome b5. It should be assumed that in this case there is an increase in the generation of reactive oxygen species, free radicals, which stimulate the development of free radical processes in the body and are, most likely, the leading link in oxidative stress. Conclusions. These changes indicate a violation of the bioenergetics of hepatocytes associated with the mitochondrial apparatus and the development of hypoxic processes, which lead to a decrease in the activity of redox reactions occurring at the level of intracellular membranes and organelles.


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