The effects of chronic cadmium exposure on the gut of Bufo gargarizans larvae at metamorphic climax: Histopathological impairments, microbiota changes and intestinal remodeling disruption.

In this study, we examined the effects of chronic cadmium exposure on the gut of tadpoles at Gosner stage 42 of metamorphic climax by using Bufo gargarizans as a model species. Tadpoles were exposed to cadmium concentrations at 0, 5, 100 and 200 μg L-1 from Gosner stage 26-42. The results showed that high cadmium (100 and 200 μg L-1) exposure caused significant decrease of body length and weight but significant increase of intestinal length and weight. Moreover, severe histopathological damages were induced by high Cd exposure. In addition, microbial communities in the gut of tadpoles in high cadmium exposure groups were remarkably different from those in control group. Unexpectedly, species diversity and richness were higher in the intestinal microbiota of 200 μg L-1 cadmium exposure group. Furthermore, the abundance of prevalent phyla, families and genera of intestinal microbiota were changed by cadmium exposure. Meanwhile, cadmium exposure perturbed gut renewal functions and the relative mRNA expression of genes involved in canonical and non-canonical Wnt signaling pathway was seriously affected by high cadmium exposure. We concluded that cadmium could be harmful to tadpole health by inducing intestinal histopathological damages, gut remodeling inhibition and intestinal microbiota alterations. PMID: 32222598 [PubMed - as supplied by publisher]
Source: Ecotoxicology and Environmental Safety - Category: Environmental Health Authors: Tags: Ecotoxicol Environ Saf Source Type: research