Chronic biliary drainage corrects liver atrophy induced by portacaval shunt in the rat

Portacaval shunt induces a severe liver atrophy. The relative liver hypertrophy induced by chronic biliary drainage was studied by electron microscopy. Rats with either portacaval or sham portacaval shunt had a 4-day chronic bile fistula. Compared with rats not submitted to chronic bile fistula, liver weight/body weight ratio increased from 1.84 to +/- 0.12 to 3.54 +/- 0.48 (p less than 0.05) in portacaval shunt and from 3.52 +/- 0.15 to 3.64 +/- 0.40 (p less than 0.05) in sham portacaval shunt (controls). Chronic bile fistula stimulated bile acid synthesis in the two groups. Furthermore, the initial low bile flow observed in portacaval shunt (rats) reached control values after chronic bile fistula. Ultrastructural abnormalities observed in portacaval shunt: atrophy of the hepatocyte mainly related to the atrophy of the rough and smooth endoplasmic reticulum, irregularity of the nucleus, dilatation of the nuclear envelope and of the rough endoplasmic reticulum, and swelling of mitochondria, were greatly modified by chronic bile fistula. The hepatocyte size increased, mitochondria appeared smaller than normal, the nuclear envelope and the rough endoplasmic reticulum were not dilated, and the rough and smooth endoplasmic reticulum were expanded. Chronic bile fistula had no noticeable effect on the liver in sham portacaval shunt. Either stimulation of bile salts synthesis or removal of bile salts, which could be toxic for the atrophic liver, are possible explanations for the relative hypertrophy of the liver.