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Stimulation of prostaglandin synthesis in cultured liver cells by CCl 4
Author(s) -
Johnston D E,
Kroening C
Publication year - 1996
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.510240334
Subject(s) - hepatocyte , prostaglandin , cyclooxygenase , lipid peroxidation , chemistry , liver injury , carbon tetrachloride , prostaglandin e2 , biochemistry , medicine , thromboxane b2 , endocrinology , microbiology and biotechnology , biology , in vitro , enzyme , platelet , organic chemistry
The contribution of hepatocytes to liver prostaglandin synthesis is controversial, partly because hepatocytes of varying purity have been studied. In this study, prostaglandin synthesis was examined in conventional and ricin‐purified rat hepatocytes that were incubated with gaseous carbon tetrachloride as a model stimulus for lipid peroxidation and prostaglandin synthesis. Hepatocytes that were incubated for 2 hours with 1 ml, of liquid CCl 4 /5 L gas volume showed no evidence of cell death or injury. However, twice this volume of CCl 4 caused total cell death. Enzyme immunoassay (EIA) failed to detect prostaglandin E 2 (PGE 2 ) synthesis in hepatocyte cultures after the first day in culture, under a variety of cell culture conditions. Conventional hepatocyte cultures, but not ricin‐purified hepatocytes, synthesized thromboxane B 2 (approximately 300 pg/mg protein) and prostaglandin D 2 (PGD 2 ) (range, 1,000‐6,000 pg/mg protein). Conventional hepatocyte cultures released prostaglandin F 2α; (PGF 2α ) immunoreactivity (ranging from approximately 900 to 1,800 pg/mg protein). Ricin‐purified hepatocyte cultures made at least half as much PGF 2α immunoreactivity as did corresponding conventional hepatocytes. However, cyclooxygenase inhibitors did not inhibit the portion of PGF 2α immunoreactivity made by ricin‐purified hepatocytes. PGF 2α immunoreactivity released by ricin‐purified hepatocytes cochromatographed with PGF2 α, and probably represents F2‐isoprostanes resulting from lipid peroxidation in hepatocytes. F2‐ isoprostane release was detected by immunoassay. Conventional cultures of rat hepatocytes contain Kupffer and endothelial cells, which can synthesize significant amounts of cyclooxygenase products. Highly purified hepatocytes do not produce cyclooxygenase products, even with a maximal stimulus to lipid peroxidation. CCl 4 causes the release of F2‐isoprostanes from hepatocytes with or without observable cell injury, as detected by Trypan blue exclusion or lactate dehydrogenase (LDH) release.