IQUIBICEN   23947
INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CIENCIAS EXACTAS Y NATURALES
Unidad Ejecutora - UE
artículos
Título:
Effects of paralytic shellfish toxins on the middle intestine of Oncorhynchus mykiss: glutathione metabolism, oxidative status, lysosomal function and ABCC proteins activity?
Autor/es:
KROCK, B.; LUQUET, C.; KROCK, B.; LUQUET, C.; BIANCHI, V.; KRISTOFF, G.; BIANCHI, V.; KRISTOFF, G.; PAINEFILÚ, J.; DE ANNA, J.; PAINEFILÚ, J.; DE ANNA, J.
Revista:
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
Editorial:
ACADEMIC PRESS INC ELSEVIER SCIENCE
Referencias:
Lugar: Amsterdam; Año: 2020 vol. 204
ISSN:
0147-6513
Resumen:
We studied the absorption, cytotoxicity and oxidative stress markers of Paralytic Shellfish Toxins (PST) from three extracts from Alexandrium catenella and A. ostenfeldii, in middle Oncorhynchus mykiss intestine in vitro and ex vivo preparations. We mwasured glutathione (GSH) content, glutathione-S transferase (GST), glutathione reductase (GR) and catalase (CAT) enzymatic activity, and lipid peroxidation in isolated epithelium exposed to 0,13 and 1,3 µM PST. ROS production and lysosomal membrane stability (as neutral red retention time 50 %, NRRT50) were analysed in isolated enterocytes exposed to PST alone or plus 3 µM of the ABCC transport inhibitor MK571. In addition, the concentration-dependent effects of PST on NRRT50 were assayed in a concentration range from 0 to 1,3 µM PST. We studied the effects ot three PST extracts on the transport rate of the ABCC substrate DNP-SG by isolated epithelium. The extract with highest inhibition capacity was selected for studying polarized DNP-SG transport in everted and non-everted intestinal segments. We registered lower GSH content and GST activity, and higher GR activity, lipid peroxidation and ROS level. PST exposure decreasd NRRT50 in a concentration-depend manner (IC50=0,0045 µM), but PST effects were not augmented by addition of MK571. All the three PST extracts inhibited ABCC transport activity, but this inhibition was effective only when the toxins were applied to the apical side of the intestine and DNP-SG transport was measured at the basolateral side. Our results indicate that PST are absorbed by the enterocytes from the intestine lumen. Inside the enteroytes these toxins decrease GSH content and inhibit the basolateral ABCC transporters affecting the normal functions of the cell. Furthermore, PST produce a strong cytotoxic effect to the enterocytes by damaging the lysosomal membrane, even at low, non-neurotoxic concentrations.