Alterations in hepatocyte plasma membrane in carbon tetrachloride poisoning. Freeze-fracture analysis of gap junction and electron spin resonance analysis of lipid fluidity.
The plasmalemma of the livers of rats treated with carbon tetrachloride (CCl4) were examined by freeze-fracture and electron spin resonance probe techniques. The rodents received by mouth either mineral oil alone (0 to 4.5 hours before sacrifice) or CCl4 in mineral oil (1:1) (2.5 ml of CCl4/kg, 0 to 3 hours before sacrifice). Rats were anesthetized with ether and livers were perfused in situ with saline either at ambient temperature or at 4 degrees C. After perfusion, livers were fixed in situ and processed for freeze-fracture and electron microscopy. Hepatocytes were isolated and incubated with 12-doxylstearic acid and subjected to electron spin resonance analysis. Electron microscopy revealed greater than a 2.5-fold increase in the individual mean gap junction size when rats were treated with mineral oil alone for 4.5 hours and the livers were processed at room temperature. The mean gap junction size in rats dosed with CCl4 for 0.5 hours before sacrifice equalled those of the group treated with mineral oil for 4.5 hours. Increases in gap junction size with CCl4 were progressive with time; by 3 hours, a 3.5-fold increase over controls was observed (p less than 0.05). When livers were perfused with iced saline, rats treated with mineral oil for 1.5 hours had a slight decrease (not significant) in mean gap junction size as compared to controls, while the size in rats treated for the same amount of time with CCl4 increased almost 5-fold over controls (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D002252:Carbon Tetrachloride Poisoning / Q000473:pathology*; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D005614:Freeze Fracturing; D007365:Intercellular Junctions / Q000187:drug effects / Q000648:ultrastructure; D008099:Liver / Q000187:drug effects* / Q000648:ultrastructure; D008297:Male; D008560:Membrane Fluidity / Q000187:drug effects*; D008899:Mineral Oil / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013113:Spin Labels
D003497:Cyclic N-Oxides; D013113:Spin Labels; C037404:12-doxylstearic acid; D008899:Mineral Oil