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Updated: Aug 19, 2026

Pseudomonas aeruginosa Induced Lung Injury Model
07:24

Pseudomonas aeruginosa Induced Lung Injury Model

Published on: October 29, 2014

Pathophysiologic effects of a toxic peptide from Microcystis aeruginosa

W H Adams, R D Stoner, D G Adams

    Toxicon : Official Journal of the International Society on Toxinology
    |January 1, 1985
    PubMed

    Insights

    Hepatocellular damage from CCl4 protects mice from acute Toxin-LR death. However, hydrocortisone prevents both acute and delayed deaths, suggesting a role beyond direct liver toxicity for this cyanotoxin.

    Area of Science:

    • Toxicology
    • Pharmacology
    • Hepatology

    Background:

    • Microcystis aeruginosa produces Toxin-LR, a hexapeptide known for acute toxicity.
    • Toxin-LR causes hepatic vascular congestion, thrombocytopenia, and pulmonary thrombi, leading to rapid death in mice.
    • Its classification as solely an hepatotoxin is questioned by observed protective mechanisms.

    Purpose of the Study:

    • To investigate the protective effects of prior hepatocellular damage on Toxin-LR lethality.
    • To explore the role of microsomal enzymes and hydrocortisone in Toxin-LR toxicity.
    • To determine if Toxin-LR directly affects platelet aggregation or induces a humoral factor.

    Main Methods:

    • Mice were pretreated with carbon tetrachloride (CCl4) to induce hepatocellular damage before Toxin-LR administration.
    • Mice were pretreated with microsomal enzyme inhibitors (SKF 525A, cobaltous chloride) and hydrocortisone.
    • Effects of X-irradiation-induced thrombocytopenia on lethality were assessed.
    • In vitro platelet aggregation and detection of humoral factors in plasma were performed.

    Main Results:

    • Sublethal CCl4 pretreatment prevented acute Toxin-LR deaths, but delayed mortality increased.
    • Microsomal enzyme inhibitors did not alter acute lethality.
    • Pharmacologic doses of hydrocortisone prevented both acute and delayed deaths.
    • Thrombocytopenia or leukopenia did not significantly affect Toxin-LR lethality.
    • No in vitro platelet aggregation or lysis was observed; no humoral aggregating factor was detected.

    Conclusions:

    • Hepatocellular damage can mitigate acute Toxin-LR lethality, indicating a complex toxic mechanism.
    • Hydrocortisone demonstrates significant protective effects against both acute and delayed Toxin-LR toxicity.
    • Toxin-LR's lethality is not solely dependent on direct platelet effects or induced humoral factors.

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