Induction of micronuclei in peripheral erythrocytes of axolotl larvae following in vivo exposure to mutagenic agents.
Previous work from this laboratory demonstrated the presence of micronuclei in erythrocytes from larvae of the urodele amphibian Pleurodeles waltl reared in water containing clastogenic substances. In order to investigate the generality of this finding, larvae from another urodele Ambystoma mexicanum (axolotl) were reared in water containing one of the two following compounds: benzo[a]pyrene (BaP) or ethylmethane sulphonate (EMS). The level of micronucleated erythrocytes on blood smears was compared with control samples from larvae reared in fresh water. The optimum larval stage for this test system was determined. The effects of the indirect mutagen (BaP), and the direct mutagen (EMS) were found to depend on both dose and exposure to the clastogen. Positive results were obtained for BaP after 8 days of treatment at a concentration of 0.025 p.p.m. After 10 days of treatment at a concentration of 0.1 p.p.m. numerous micronuclei were seen (greater than 250%). Positive results were also obtained with EMS after 8 days of treatment at a concentration of 24 p.p.m. At 62 p.p.m., positive results were found after 6 days of treatment, while at 124 p.p.m. positive results were found after only 4 days. The results with both these agents show that the axolotl holds promise as an in vivo test system for the detection of low concentrations of clastogens in an aquatic environment.
Jaylet
A
A
Laboratoire de Biologie Générale, Université Paul Sabatier, Toulouse, France.
Deparis
P
P
Gaschignard
D
D
D000557:Ambystoma; D000558:Ambystoma mexicanum; D000818:Animals; D001564:Benzo(a)pyrene / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D009152:Mutagenicity Tests; D014876:Water Pollution
D001564:Benzo(a)pyrene; D005020:Ethyl Methanesulfonate