[IMMUNOCYTOCHEMICAL ANALYSIS OF THE DISTURBANCES IN THE STRUCTURE OF SYNAPTONEMAL COMPLEXES IN SPERMATOCYTE NUCLEI IN MICE UNDER EXPOSURE TO ROCKET FUEL COMPONENT].

There was performed an assessment of genotoxic effects of rocket fuel component--unsymmetrical dimethylhydrazine (UDMH, heptyl)--on forming germ cells of male mice. Immunocytochemically there was studied the structure of meiotic nuclei at different times after the intraperitoneal administration of UDMH to male mice. There were revealed following types of disturbances of the structure of synaptonemal complexes (SCs) of meiotic chromosomes: single and multiple fragments of SCs associations of autosomes with a sex bivalent, atypical structure of the SCs with a frequency higher than the reference level. In addition, there were found the premature desinapsis of sex bivalents, the disorder offormation of the genital corpuscle and ring SCs. Established disorders in SCs of spermatocytes, analyzed at 38th day after the 10-days intoxication of animal by the component of rocket fuel, attest to the risk of permanent persistence of chromosomal abnormalities occurring in the pool of stem cells.

[Genotoxic effects of pesticide fipronil in somatic and generative cells of mice].

The pronounced genotoxic effect of fipronil in all used doses (4.75, 9.50, 19.00, and 31.70 mg/kg) at a single exposure in the liver, lungs and spleen was ascertained by the Comet assay. Organ specificity of genotoxic effects of the pesticide was revealed. The liver was the most sensitive to fipronil. Fipronil at a dose of 9.50 mg/kg in a single and repeated exposure (within 10 days) induced aberrations in mouse bone marrow cells with the frequency exceeding the spontaneous mutation rate (p < 0.01 and p < 0.001, respectively). Fipronil also showed genotoxic activity in the germ cells of the experimental animals, causing abnormalities of the structure of synaptonemal complexes in the spermatocytes.