Accession Number:

ADA218039

Title:

Toxin-Induced Activation of Rat Hepatocyte Prostaglandin Synthesis and Phospholipid Metabolism

Descriptive Note:

Interim rept.

Corporate Author:

ARMY MEDICAL RESEARCH INST OF INFECTIOUS DISEASES FORT DETRICK MD

Report Date:

1989-12-22

Pagination or Media Count:

20.0

Abstract:

The effects of microcystin-LR a trichothecene T-2 toxin and saxitoxin on membrane lipid mediators of inflammatory processes were evaluated in cultured rat hepatocytes. Microcystin-LR significantly stimulated the release of prostacyclin and thromboxane B2 in a concentration-dependent manner. The trichothecene toxin, T-2, enhanced the release of prostaglandin F2a PGF2a by 24 p 0.05 and arachidonic acid by 29 p 0.05 while saxitoxin failed to cause the release of prostaglandins or arachidonic acid. Incorporation of arachidonic acid into the lipid pool was reduced to 47 p 0.025 by 1 micromole microcystin-LR. Changes in phospholipid classes indicated that prostaglandin formation induced by microcystin-LR was due to the release of arachidonic acid from the phosphatidylinositol pool. A 10 increase in phosphatidylcholine in hepatocytes treated with microcystin-LR may have resulted from conversion of phosphatidylethanolamine to phosphatidylcholine via the N- methylation pathway. These results indicate that microcystin-LR has important effects on the regulation of inflammatory mediator synthesis in hepatocytes. AW

Subject Categories:

  • Biochemistry
  • Toxicology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE