CADMIUM EFFECTS ON GLYCAN CONTENT IN DANIO RERIO GUT MUCOSA

Cadmium is a widespread environmental contaminant extremelytoxic for plants and animals. By inducing oxidative damage1, itinterferes with behavior and tissue organization2. In the gut, italso compromises the microbiota thus reducing mucosal efficien-cy as barrier and causing inflammation and metabolic disorders3.Toxicity is particularly severe in aquatic organisms exposed fromovo to death via multiple routes, skin, gut and gills in particular4.In the present work we studied the effects of waterborne cadmi-um chloride (25 and 100 μM, 30 days) on gut mucosa of Daniorerio. Particular attention was dedicated to changes in glycanresidues distribution. Glycans in fact play fundamental roles incell-cell interaction and signaling, and in gut mucus properties,contributing diverse biologic properties to the mucosa. WGA,PNA and RCA fluorescent lectins5 were used to highlight inter-ferences in N-acetyl-glucosamine, N-acetyl-galactosamine andgalactose distribution while mucosal defense response was deter-mined by analyzing metallothionein expression via immunocyto-chemistry. Results demonstrate that cadmium induces extensiveseric infiltration in the villi but not blood stasis or hemorrhage.Cadmium modifies the presence and/or distribution of glycans inenterocytes brush border and cytoplasm and in the goblet cellscytoplasm. The effects are dose and site dependent the anteriorgut being more markedly influenced than the mid gut.Metallothionein, concentrated in the apical cytoplasm of entero-cytes, markedly reduces at the higher dose. Results suggest a sig-nificant interference of cadmium with mucosal efficiency.