title: Comparative cytopathology of primary rat hepatocyte cultures exposed to aflatoxin B1, acetaminophen, and other hepatotoxins.
abstract: The cytomorphological alterations in primary monolayer cultures of Fischer 344 rat hepatocytes exposed continuously to lethal concentrations of various hepatotoxins were compared. Aflatoxin B1 (AFB1) at concentrations of 1 and 10 microM killed 67 and 97% hepatocytes, respectively, at 48 hr, as determined by release of lactate dehydrogenase (LDH) into culture medium, or by trypan blue uptake. AFB1 produced numerous radial finger-like projections (blebs) at attached margins of cytoplasm in almost all hepatocytes between 6 and 24 hr. Formation of blebs was dose dependent and preceded release of LDH and trypan blue uptake. Similar marginal blebs were produced by cycloheximide, 2-acetylaminofluorene, N-hydroxy-2-acetylaminofluorene, and senecionine. By comparison, acetaminophen, at equivalently lethal concentrations (4 or 16 mM) did not cause marginal blebs, but resulted in a similar time course of LDH release and trypan blue uptake. Carbon tetrachloride and bromobenzene also failed to produce blebs at lethal concentrations. Phalloidin and cytochalasin B rapidly produced smaller spherical blebs over the entire surface of all hepatocytes, distinct from the finger-like blebs produced only at the free attached margins of cells exposed to AFB1. Blebs and lethal injury by AFB1 were reduced by phenobarbitone or 3-methylcholanthrene pretreatments and by SKF-525-A in culture. The demonstration of morphological prelethal changes in hepatocytes injured by different classes of hepatotoxins in culture provides a means of differentiating the early biochemical mechanisms by which hepatotoxins and hepatocarcinogens lethally injure hepatocytes before membrane permeability to LDH and trypan blue is detectable.
mesh_terms: D000082:Acetaminophen / Q000633:toxicity; D016604:Aflatoxin B1; D000348:Aflatoxins / Q000633:toxicity*; D000818:Animals; D002478:Cells, Cultured; D004121:Dimethyl Sulfoxide / Q000633:toxicity; D064420:Drug-Related Side Effects and Adverse Reactions; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000473:pathology; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D014343:Trypan Blue / Q000378:metabolism
chemical_list: D000348:Aflatoxins; D000082:Acetaminophen; D016604:Aflatoxin B1; D007770:L-Lactate Dehydrogenase; D014343:Trypan Blue; D004121:Dimethyl Sulfoxide