[Experimental sclerosing cholangitis following intrabiliary injection of formol in the rat].

Our study was aimed at assessing the effect on the biliary epithelium of formol and hypertonic salt serum solutions used as parasiticide for hydatid cysts of the liver in rats. One hundred and forty six rats were administrated an intrabiliary injection of isotonic salt serum (control group), of 20% hypertonic salt serum and of 0.5% and 2% formol solutions. A histological study performed 3 months later did not show any abnormality in the rat control group (n = 11). In the hypertonic salt serum group (n = 14) and 0.5% formol group (n = 12), moderate lesions of biliary epithelium were observed. After a 2% formol injection, a periductal sclerosis was observed in 11 cases out of 16, associated with pseudocirrhosis lesions in 4 cases. A sequential histo-immunochemical study did not show any histological abnormalities in the rat control group (n = 24). In rats which were administrated a 2% formol solution (n = 36), first abnormalities were observed as soon as the 7th day with a IA antigen expression at the biliary epithelium level. Fibrosis lesions were observed after 2 months. After 9 months, the infiltration included only T lymphocytes in direct contact with biliary tracts. A cholangiographic study showed a normal aspect in the rat control group (n = 11) or in rats having received hypertonic salt serum (n = 11), and stenoses of biliary tracts, mainly intrahepatic, in 10 rats out of the 11 of the 2% formol group.(ABSTRACT TRUNCATED AT 250 WORDS)