Systemic and gonadal disruption caused by daily exposure to 3-methylcholanthrene in male rats

FALETTI, ALICIA G.; RHON CALDERÓN, ERIC A.; GALARZA, ROCÍO A.

Sevilla

Congreso; 52nd Congress of the European Societies of Toxicology (EUROTOX); 2016

Sociedad Europea de Toxicología

3-Methylcholanthrene (3MC), an environmental pollutant, is a polyaromatic hydrocarbon that causes reproductive toxicity in different organisms. Previous studies showed that 3MC alters the ovarian function by affecting the follicle integrity in rodents. The aim of this work was to study whether a daily exposure to 3MC affects the reproductive capacity in males by examining both quality and quantity of sperm. To this end, testis from immature rats, daily exposed to 3MC (1 mg/kg) for 20 days were used. 3MC animals exhibited a decrease in sperm count, expressed as million cells/ml (80 ± 26, p < 0.05), and an increase in sperm abnormalities, expressed as percentage of total sperm (9 ± 1, p < 0.01), compared with controls (185 ± 16 and 1.6 ± 0.4, respectively). No changes were found in the body, epididymal or testicular weight. To study whether the 3MC exposure causes systemic toxicity, two genotoxic methodologies were used in peripheral blood (PB), bone marrow (BM) and sperm: micronucleus (MN) test in 1000 polychromatic erythrocytes, and the comet assay by measuring the length of DNA migration and the percentage of migrated DNA. 3MC treatment induced (i) the formation of MN (27 ± 7, p < 0.01) compared with controls (2.5 ± 1.4); and (ii) a higher tail DNA percentage in BM (6.87 ± 0.06), PB (4.16 ± 0.08) and sperm (16 ± 2), when compared with controls (0.97 ± 0.14; 0.86 ± 0.07; 6.3 ± 0.4; respectively, p < 0.01). These results indicate that a daily exposure to low doses of 3MC: (i) alter the reproductive capacity by increasing the morphological abnormalities and decreasing the total sperm, and (ii) increase the risk of carcinogenic processes by altering the DNA.