Micronucleus induction in mouse peripheral reticulocytes by 7,12-dimethylbenz[a]anthracene

Area of Science:

• Toxicology
• Genetics
• Hematology

Background:

• Micronucleus assays are crucial for detecting genotoxicity.
• Standard bone marrow assays can be labor-intensive.
• Peripheral blood assays offer a less invasive alternative.

Purpose of the Study:

• To evaluate the acridine orange (AO) supravital staining method for micronucleus assays using mouse peripheral blood.
• To compare this method with the standard bone marrow assay.
• To assess the feasibility of obtaining dose- and time-response data for chemical-induced genotoxicity.

Main Methods:

• Mice were administered 7,12-dimethylbenz[a]anthracene (DMBA) intraperitoneally at varying doses.
• Peripheral blood was sampled at multiple time points (24-120 h) post-treatment.
• Blood samples were stained with AO for micronucleated reticulocyte analysis.
• Results were compared with concurrent bone marrow micronucleus assays.

Main Results:

• Similar incidences of micronucleated young erythrocytes were observed in peripheral blood reticulocytes and bone marrow polychromatic erythrocytes.
• The dose response for micronucleated reticulocytes was delayed compared to bone marrow cells.
• Dose-response curves varied with sampling times, indicating potential challenges in accurate relation determination.

Conclusions:

• The AO supravital staining method is a valuable, simpler, and rapid technique for micronucleus assays.
• This method facilitates easier acquisition of dose- and time-response data for genotoxicity assessment.
• It presents a practical alternative for quantifying micronucleus induction by chemicals.