Early morphological and functional alterations in canine hepatocytes due to alpha-amanitin, a major toxin of Amanita phalloides.
The toadstool death cap (Amanita phalloides) and its subspecies, destroying angel (A. virosa) and death angel (A. verna) are responsible for nearly 95% of all fatal mushroom poisonings. High mortality rate in A. phalloides intoxications is principally a result of the acute liver failure following significant hepatocyte damage due to hepatocellular uptake of amanitins, the major toxins of this mushroom. This study evaluated early morphological and functional alterations in hepatocytes exposed to different concentrations of alpha-amanitin (alpha-AMA). All experiments were performed on cultured canine hepatocytes since intoxicated with A. phalloides dogs have clinical course and pathological findings similar to those seen in humans. The overall functional integrity and viability of cultured hepatocytes were assessed using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and by measurements of lactate dehydrogenase (LDH), total protein, and urea levels. Our results showed that the course of alpha-AMA toxicity in cultured dog hepatocytes is divided into two phases. The first phase comprises functional cell impairments expressed by significant increase of LDH activity and inhibition of protein and urea synthesis when compared with the control group. This is followed by discrete changes in hepatocyte ultrastructure, including marginalization and condensation of nuclear chromatin, as well as formation of the foamlike cytoplasm. The second stage is lethal and is characterized by ongoing necrosis, and/or apoptosis. This may be related to dose of toxin and time of exposure.
Magdalan
Jan
J
Department of Pharmacology, Wrocław Medical University, Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland.
Ostrowska
Alina
A
Podhorska-Okołów
Marzena
M
Piotrowska
Aleksandra
A
Izykowska
Ilona
I
Nowak
Marcin
M
Dolińska-Krajewska
Barbara
B
Zabel
Maciej
M
Szelag
Adam
A
Dziegiel
Piotr
P
D053959:Alpha-Amanitin / Q000008:administration & dosage / Q000302:isolation & purification / Q000633:toxicity*; D000545:Amanita / Q000737:chemistry*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D007770:L-Lactate Dehydrogenase / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009336:Necrosis / Q000139:chemically induced; D013997:Time Factors; D018675:Toxicity Tests; D014508:Urea / Q000378:metabolism
D053959:Alpha-Amanitin; D002843:Chromatin; D014508:Urea; D007770:L-Lactate Dehydrogenase