Abstract

PLAZAS, G.D. et al. Cyto andxeno toxicity in turtle Trachemys sp erythrocytes subjected to different concentrations of metilmercury. Rev. vet. [online]. 2022, vol.33, n.1, pp.32-40. ISSN 1669-6840.  http://dx.doi.org/10.30972/vet.3315876.

20.

Methyl mercury (MeHg) is a xenobiotic that bio- accumulates and bio-magnifies in the food chain. The Trachemys scripta elegans (Tse) turtle is considered a sentinel of environmental pollution because of its longevity. Tse has nucleated erythrocytes (RBCs) with 90% affinity for MeHg. This study determined cyto-toxicity and geno-toxicity in vitro of MeHg on Tse RBCs at concentrations of 0, 0.5, 0.7, 1, 10, 20, 50 and 100 m g L -1 at 24 and 96 h of exposure. The RBCs were isolated by centrifugation and 1.69 x106 RBCs per treatment were used. The percentage of viability, mean lethal concentration (LC50) and cytological changes were determined at 24 and 96 h. It was evaluated the xeno toxicity by RAPDs markers with extracted DNA at 96 h, calculating the percentage of polymorphism, index of genetic stability (GST) and coefficient of Jaccard dissimilarity (dJSC). At 96 h, viability was maintained between 99-0% in 0.5-100 mg L-1 of MeHg. The LC50 was 22.55 mg L-1 MeHg. Cytological abnormalities were presented in 0.7-100 m g L -1 MeHg as crescent shape, cytoplasmic inclusions, membrane fading, eccentric nuclei and cell lysis. The polymorphism was 85-50% and the dJSC was 0.5-0.63 in 50-100 m g L -1 MeHg compared to the control group. GST decreased to 42% at 100 m g L -1MeHg. It is concluded that MeHg is cytotoxic and genotoxic at concentrations greater than 10 mg L-1 in Tse RBCs. This study represents a baseline for Hg toxicological studies in reptile RBCs.

Keywords : Trachemys scripta elegans; erythrocytes; lethal dose 50; genetic stability; metyl mercury.

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