Actin filament alteration as a potential marker for cholestasis: a study in isolated rat hepatocyte couplets.
It has been suggested that modification of the pericanalicular microfilament network (F-actin) plays a role in cholestasis. The purposes of this study were to assess (i) the process of F-actin network reorganization in isolated rat hepatocyte couplets (IRHC) in order to define the optimal study conditions in this model, (ii) the effect of cholestatic and hepatotoxic but non-cholestatic compounds on F-actin distribution in IRHC. F-actin was stained with fluorescein isothiocyanate phalloidin and fluorimetric measurements were performed in single couplets using a scanning laser cytometer, ACAS 570. F-actin distribution was assessed by the ratio of canalicular area fluorescence/total couplet fluorescence (CF/TF). The organization of the F-actin filaments was restored in IRHC 3-6 h after plating. At non-cytotoxic concentrations, most cholestatic compounds induced a significant accumulation of F-actin around the bile canaliculus as indicated by increased fluorescence in the pericanalicular area and by the increased CF/TF ratio as compared to the controls. This accumulation could be a consequence of an inhibition of F-actin depolymerization or a higher organization of actin (redistribution, bundling or reorientation). Hepatotoxic but non-cholestatic compounds did not induce any change in pericanalicular F-actin. Abnormalities of pericanalicular F-actin therefore appear to be a specific marker of hepatocellular cholestasis.
Thibault
N
N
Drug Safety Department, Rhône-Poulenc Rorer, Vitry sur Seine, France.
Claude
J R
JR
Ballet
F
F
D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D000818:Animals; D001647:Bile Acids and Salts / Q000494:pharmacology; D002478:Cells, Cultured; D002779:Cholestasis / Q000378:metabolism*; D004917:Erythromycin / Q000494:pharmacology; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D000199:Actins; D001647:Bile Acids and Salts; D004917:Erythromycin