The role of metallothioneins, selenium and transfer to offspring in mercury detoxification in Franciscana dolphins (Pontoporia blainvillei)

ROMERO, MA. BELEN; POLIZZI, PAULA ; CHIODI BOUDET, LEILA; DAS, KRISHNA; GERPE, MARCELA

MARINE POLLUTION BULLETIN

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2016

0025-326X

The concentration of mercury (Hg), selenium (Se) and metallothioneins (MT) were evaluated in fetuses, calves, juveniles and adults of the endangered coastal dolphin Pontoporia blainvillei from Argentina. Mercury levels varied among analyzed tissues (liver, kidney, muscle and brain), with liver showing the higher concentrations of all specimens. An age-dependent accumulation was found in liver, kidney and brain. No significant relationship between Hg and MT concentrations was found for all tissues analyzed. Hepatic Hg molar concentrations were positively correlated with those of Se, indicating a great affinity between these two metals. Furthermore, dark granules were observed in Kupffer cells in the liver by electron microscopy, confirming the role of this macrophage in the detoxification of Hg. A transfer of this metal through placenta was proved. The presence of Hg in brain in all age classes suggests a potential neurotoxic effect in the species.