Ewha Med J.  1980 Sep;3(3):113-118. 10.12771/emj.1980.3.3.113.

The Effects of Vitamin B Complexes on AAF Hydroxylation by Rat Liver Microsomal Cytochrome P-450

• Hong YS
• Kim BH
• Sung NE

• KMID: 1969574
• DOI: http://doi.org/10.12771/emj.1980.3.3.113

Abstract

The effects of vitamin B complexes on both ring and N-hydroxylation of 2-ace-tylaminofluorene by rat hepatic microsomal fraction were studied. In the presence of thiamine-Hcl during incubation, the total hydroxy-AAF was increased by 50.3%. 0.1mM and 1.0mM riboflavin inhibited only total hydroxy-AAF with 56.7% and 85.0 whereas N-hydroxy AAF was increased to some extent. 1.0mM niacin did not have much effect on the total hydroxy-AAF, but 0.1mM niacin decreased the total dydroxy-AAF by 28.6%. Presence of p-amino-benzoic acid, calcium pantothenate, pyridoxal-Hcl or vitamin B12 inhibited the total hydroxy-AAF to some extent. But the radio of ring-and N-AAF hydroxylation was not changed by these vitaminn B complexes. Our present results suggest that vitamin B complexes were not effective in vitro metabolism of 2-AAF to N-hydroxy AAF(activation step of AAF) by a cytochrome p-450 dependent mixed function oxidase system.

MeSH Terms

2-Acetylaminofluorene
Animals
Cytochrome P-450 Enzyme System*
Cytochromes*
Hydroxylation*
Liver*
Metabolism
Niacin
Oxidoreductases
Pantothenic Acid
Rats*
Riboflavin
Vitamin B 12
Vitamin B Complex*
Vitamins*
2-Acetylaminofluorene
Cytochrome P-450 Enzyme System
Cytochromes
Niacin
Oxidoreductases
Pantothenic Acid
Riboflavin
Vitamin B 12
Vitamin B Complex
Vitamins