Effects of dinophysistoxin-2 on the ultrastructure of mice intestinal and liver cells

Okadaic acid (OA) and the closely related dinophysistoxins (DTXs) are algal toxins that accumulate in shellfish. The consumption of this shellfish can induce the diarrheic shellfish poisoning (DSP) in humans, which symptoms... [ view full abstract ]

Okadaic acid (OA) and the closely related dinophysistoxins (DTXs) are algal toxins that accumulate in shellfish. The consumption of this shellfish can induce the diarrheic shellfish poisoning (DSP) in humans, which symptoms are diarrhea, nausea, vomiting and abdominal pain. Toxic episodes have become more frequent and intense over the years, affecting new areas due to dispersion of the producing organisms such as dinoflagellates of the Prorocentrum and Dinophysis genera. Exposure effects of OA, the main representative DSP toxin, have been previously investigated. However, there is scarce information about oral toxicity of DTX2. The aim of this work was to study the ultrastructural alterations of mice intestinal and liver cells after administration of DTX2 by gavage. Necroscopy revealed dose dependent swelling with fluid accumulation in stomach and intestine. Ultrastructural changes were found on intestinal and liver cells by transmission electron microscopy (TEM) imaging. The oral treatment with DTX2 caused dilation of rough endoplasmic reticulum and mitochondria as well as higher presence of endosomes in small intestine cells, although enterocytes microvilli and tight junctions were not altered. In large intestine DTX2 induced electron-dense granules inside some mitochondria. Additionally liver was injured showing hepatocytes with autophagosomes and a reduction of glycogen granules.