| Autor: |
Menkveld, Gerda J., Laken, Cornelis J. Van Der, Hermsen, Trudi, Kriek, Erik, Scherer, Ewalt, Engelse, Leo Den |
| Zdroj: |
Carcinogenesis; 1985, Vol. 6 Issue 2, p263-270, 8p |
| Abstrakt: |
Antibodies raised in rabbits against the bovine serum albumin conjugates of O-ethylguanosine (O-EtGuo) and N-(guanosin-8-yl)-N-acetyl-2-aminofluorene (Guo-8-AAF) have been used in a double peroxidase-antiperoxidase staining assay to visualize the localization of DNA-O-ethyldeoxyguanosine (O-EtdGuo) and some of the interaction products of N-acetyl-2-aminofluorene (AAF) with DNA guanine in liver sections of rats treated with diethylnitrosamine (DEN), ethylnitrosourea (ENU), or AAF respectively. O-EtdGuo could be detected in nuclei of parenchymal cells after injection of DEN (12 – 50 mg/kg) or ENU (140 mg/kg). Clear time and dose dependencies were observed. The lowest dose of DEN which, at 5 h after injection, resulted in immunohistochemically detectable levels of O-EtdGuo, was 12 mg/kg; 5 h after 6 mg/kg no consistent difference between treated and untreated rats could be observed. A striking heterogeneity in staining pattern was observed after DEN: centrilobular regions were stained much more than peripheral zones. At 7 days after a single DEN injection of 50 mg/kg small rims of significantly stained hepatocytes could still be observed around the central veins. No heterogeneity of staining pattern was observed 2 h after ENU. ENU, in contrast with DEN, also resulted in a significant staining of nonparenchymal cells. At 24 h after ENU no significant staining of hepatocytes could be detected, but positive staining was still present in bile duct cells, vascular endothelial cells and sinusoidal cells. The results indicate a detection level of ∼5 μmol O-EtdGuo/mol DNA-P, i.e., 5 × 10 O-EtdGuo residues per diploid genome. Using the anti-Guo-8-AAF antiserum, positive results were obtained 6 days after a single AAF dose of 0.5 – 10 mg/kg, corresponding to a detection limit of ≦0.4 μmol dGuo-8-(A)AF/mol DNA-P. Staining was rather homogenously distributed over the liver lobules. Persistency of the AAF-DNA interaction products was investigated both after 10 and 2 mg/kg AAF. Increased nuclear staining could be observed up to 8 weeks after 10 mg/kg and 4 weeks after 2 mg/kg. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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