Combination effects of clastogens in the mouse peripheral blood micronucleus assay.

In order to study how two chemicals interact to induce micronuclei, simple ethylating agents [ethyl methanesulfonate (EMS), ethyl ethanesulfonate (EES) and N-ethyl-N-nitrosourea (ENU)], spindle poisons [vincristine sulfate (VINC) and colchicine (COL)] and an oxidizing agent [potassium bromate (KBrO3)] were used as model chemicals for combination treatments. The frequency of micronucleated reticulocytes (MNRETs) was evaluated in mice treated with two of these chemicals at a time. The combinations of ethylating agents (EMS and EES; EMS and ENU) and of spindle poisons (VINC and COL) induced more micronuclei than those expected on an additive basis.

The micronucleus assay using peripheral blood reticulocytes from mitomycin C- and cyclophosphamide-treated rats.

It used to be believed that the use of rat peripheral blood for the micronucleus assay would be difficult because micronucleated erythrocytes are captured and destroyed by the spleen quickly. We have applied an acridine orange (AO) supravital staining method to rat peripheral blood using AO-coated glass slides. Normal and splenectomized SD rats were treated once with mitomycin C (i.

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

Micronucleus assays using mouse peripheral blood stained vitally on acridine orange (AO)-coated slides were evaluated at two laboratories with 7,12-dimethylbenz[a]anthracene (DMBA) and compared with the standard bone marrow assay. DMBA was administered by single intraperitoneal injection to CD-1 mice at doses ranging from 5 to 80 mg/kg, then 5 microliters of peripheral blood was sampled from a tail vein at 24, 48, 72, 96, and 120 h after treatment. Similar incidences of micronucleated young erythrocytes were observed in peripheral blood reticulocytes and bone marrow polychromatic erythrocytes.

Micronucleated reticulocyte induction by ethylating agents in mice.

Six model ethylating agents were tested for clastogenic potency by means of a new technique of the micronucleus assay with mouse peripheral blood cells using acridine orange (AO)-coated slides, to evaluate the test. The alkylating agents were: N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG), N-ethyl-N-nitrosourea (ENU), diethylsulfate (DES), ethyl methanesulfonate (EMS), epichlorohydrin (ECH) and ethylene dibromide (EDB). The animals were given a single intraperitoneal injection of the following doses of the chemicals: ENNG and ENU, 25, 50 and 100 mg/kg; EMS and DES, 100, 200 and 400 mg/kg body weight.

Mutagenicity of wood smoke condensates in the Salmonella/microsome assay.

Smoke condensates of woods used for food preservation and aromatization in Nigeria were tested for mutagenic activity using Salmonella typhimurium TA98 and TA100. The woods were: white mangrove (Avicennia nitida), red mangrove (Rhizophora racemosa), mahogany Khaya sp.), abura (Mitragyna ciliata), alstonia (Alstonia boonei) and black afara (Terminalia ivorensis).