PuSH - Publication Server of Helmholtz Zentrum München

Krebs, O.* ; Schäfer, B. ; Wolff, T.* ; Oesterle, D.* ; Deml, E. ; Sund, M. ; Favor, J.

The DNA damaging drug cyproterone acetate causes gene mutations and induces glutathione-S-transferase P in the liver of female Big BlueTM transgenic F344 rats.

Carcinogenesis 19, 241-245 (1998)
Publ. Version/Full Text Volltext DOI PMC
Closed
Open Access Green as soon as Postprint is submitted to ZB.
The gestagenic and antiandrogenic drug cyproterone acetate (CPA) is mitogenic, tumorigenic and induces DNA-adducts and DNA-repair synthesis in rat liver. Thus CPA is expected to be mutagenic. However in vitro mutagenicity test systems were negative. To examine whether CPA induces mutations in rat liver, the in vivo mutation assay based on Big Blue transgenic F344 rats was employed. Single oral doses of 25, 50, 75, 100 and 200 mg CPA/kg b.w. respectively were administered to female Big Blue rats. Six weeks after treatment, liver DNA was assayed for mutations. At the highest dose, 200 mg CPA/kg b.w., the frequency of (17 +/- 4) x 10(-6) spontaneous mutations was increased to a maximum of (80 +/- 8) x 10(-6) mutations. One-hundred and 75 mg CPA/kg b.w. resulted in mutation frequencies of (35 +/- 5) and (27 +/- 5) x 10(-6), respectively. The mutation frequency at doses of 50 and 25 mg CPA/kg b.w. was similar to that of vehicle treated controls. Statistical analysis of the dose-effect relationship revealed that it was not possible to decide whether a threshold dose exists or not. DNA adducts were analyzed by the 32P-postlabelling technique. The total level of the major and the two minor adducts observed in the autoradiograms increased between doses of 25 to 75 mg CPA/kg b.w. to a maximum of approximately 12,000 +/- 3000 adducts per 10(9) nucleotides. The level did not further increase significantly with 100 and 200 mg CPA/kg b.w. After CPA treatment no preneoplastic liver foci were observed. However, single glutathione-S-transferase placental form (GST-P) positive hepatocytes were observed and the frequency was dependent on the dose. These cells are not supposed to represent initiated cells, since they occurred only transiently after 6 weeks and disappeared thereafter completely. In conclusion, our results demonstrate that CPA is mutagenic in vivo. The mutation frequency increased at high CPA doses, when the increase of the DNA adduct formation had already ceased. This suggests that the mitogenic activity of CPA is required to express the mutations.
Impact Factor
Scopus SNIP
Web of Science
Times Cited
Scopus
Cited By
Altmetric
0.000
0.000
30
33
Tags
Annotations
Special Publikation
Hide on homepage

Edit extra information
Edit own tags
Private
Edit own annotation
Private
Hide on publication lists
on hompage
Mark as special
publikation
Publication type Article: Journal article
Document type Scientific Article
Keywords ALTERED FOCI; HEPATOCYTES; INDUCTION; ADDUCTS; CELLS; CULTURES; BINDING; MARKERS; ENZYME
Language english
Publication Year 1998
HGF-reported in Year 0
ISSN (print) / ISBN 0143-3334
e-ISSN 1460-2180
Journal Carcinogenesis
Quellenangaben Volume: 19, Issue: 2, Pages: 241-245 Article Number: , Supplement: ,
Publisher Oxford University Press
Reviewing status Peer reviewed
Institute(s) Institute of Molecular Toxicology and Pharmacology (TOX)
Department for Medical Information Systems (MEDIS)
Institut für Säugetiergenetik
Institute of Health Economics and Health Care Management (IGM)
PubMed ID 9498271
Scopus ID 0031927041
Erfassungsdatum 1998-12-31