Back to Search
Start Over
Cytochrome P450 decreases are correlated to increased microsomal oxidative damage in rabbit liver and primary cultures of rabbit hepatocytes exposed to AFB1.
- Source :
-
Toxicology letters [Toxicol Lett] 1999 Jan 11; Vol. 104 (1-2), pp. 117-25. - Publication Year :
- 1999
-
Abstract
- Although numerous studies report hepatic drug metabolizing enzyme alterations during aflatoxicosis, the mechanisms involved in P450 decreases remain to be established. The purpose of this work is to investigate whether increased oxidative damage revealed by the detection of malondialdehyde (MDA), lipofuscin substances, and conjugated dienes in microsomes, could explain the decreased P450 content. Studies were conducted with two different doses of aflatoxin B1 (AFB1), both in vivo in rabbits and ex vivo in primary cultures of rabbit hepatocytes, in the presence or absence of beta-naphthoflavone or rifampicin used as respective P450 inducers. Strong negative correlations were observed between MDA and P450 contents, both in vivo and ex vivo, whereas rifampicin appears to protect the hepatocytes from oxidative damage but not AFB1 toxicity. Positive correlation were also obtained between MDA formation and lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT) or alanine amino-transferase (ALAT) releases, used as non-specific markers of AFB1 toxicity. Taken together these results suggest that the dramatic decreases of cytochrome P450 observed in vivo during aflatoxicosis could be linked, at least in part, to microsomal oxidative damage.
- Subjects :
- Alanine Transaminase metabolism
Animals
Aspartate Aminotransferases metabolism
Cells, Cultured
L-Lactate Dehydrogenase metabolism
Liver cytology
Liver enzymology
Liver ultrastructure
Male
Malondialdehyde metabolism
Microsomes, Liver enzymology
Mycotoxicosis metabolism
Oxidation-Reduction
Rabbits
Aflatoxin B1 toxicity
Cytochrome P-450 Enzyme System metabolism
Liver drug effects
Microsomes, Liver drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0378-4274
- Volume :
- 104
- Issue :
- 1-2
- Database :
- MEDLINE
- Journal :
- Toxicology letters
- Publication Type :
- Academic Journal
- Accession number :
- 10048757
- Full Text :
- https://doi.org/10.1016/s0378-4274(98)00352-x