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[Review of present knowledge on the pathogenesis and pathophysiology of Amanita phalloides poisoning]
1Sekce pro mykologickou toxikologii Ceské vĕdecké spolecnosti pro mykologii, Praha.
Abstract:
The mushroom poisoning of phalloid type is caused by amatoxins, mainly by alpha-amanitine. It is a cytotoxin which acts through an indirect mechanism. It binds irreversibly the nucleolar enzyme, RNA-polymerase II in cells with intensive proteosynthesis (enterocytes in the digestive tract, hepatocytes in the liver and epithelial cells of proximal renal tubules). A tight binding of the toxin with the enzyme blocks the transcription from DNA to m-RNA and thus makes the proteosynthesis impossible. This results in the cell necrosis. Pathophysiology of the phalloid type poisoning is rather complicated, as the disorders of primarily affected organs (gastrointestinal tract, liver and kidney) produce a derangement of other remote organs and systems. After a relatively long period of latency (average 8-10 hours) the symptoms of the initial phase of the symptomatologic course of intoxication--excessive vomiting and diarrhea (during one or two days)--are observed, leading to dehydration which culminates in the hypovolemic shock. A short subsequent phase of an apparent improvement (in the 3rd day) is followed, beginning with the fourth day, by an acute failure of the liver and kidney. The cause of the failure of both the organs is the same--the toxic noxa. Therefore it is not possible to classify the coexistence of acute hepatal and renal failure as a so-called hepatorenal syndrome. The true hepatorenal syndrome is namely a potentially reversible prerenal failure accompanying a variety of serious liver diseases, namely in their terminal phase. The phalloid nephropathy, however, has two constituents.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Phalloid mushroom poisoning, caused by alpha-amanitin, inhibits RNA-polymerase II, leading to cell death and multi-organ failure. This severe intoxication affects the liver and kidneys, distinct from hepatorenal syndrome.
Area of Science:
- Toxicology
- Molecular Biology
- Pathophysiology
Context:
- Phalloid mushroom poisoning is a severe form of amatoxin intoxication.
- Alpha-amanitin is the primary causative cytotoxin.
- The mechanism involves irreversible binding to RNA-polymerase II.
Purpose:
- To elucidate the mechanism of alpha-amanitin toxicity.
- To describe the pathophysiology of phalloid mushroom poisoning.
- To differentiate phalloid nephropathy from hepatorenal syndrome.
Summary:
- Alpha-amanitin irreversibly inhibits RNA-polymerase II, blocking proteosynthesis and causing cell necrosis in the liver, kidneys, and digestive tract.
- Initial symptoms include vomiting and diarrhea, leading to dehydration and shock, followed by apparent improvement.
- Acute liver and kidney failure occur due to direct toxic effects, not a hepatorenal syndrome.
Impact:
- Clarifies the distinct pathophysiology of amatoxin-induced organ failure.
- Provides critical information for diagnosing and managing severe mushroom poisoning.
- Highlights the importance of distinguishing direct toxic nephropathy from hepatorenal syndrome.