Effect of chronic treatment with diuretics on mouse liver: a morphological and microanalytical investigation.

In an attempt to produce an animal model for the disease cystic fibrosis (CF), mice were treated chronically with the diuretics amiloride and furosemide, in order to cause chronic inhibition of transepithelial ion transport. Experiments were carried out on adult mice (2 months treatment); in addition, pregnant mice were treated with diuretics, and tissue from offspring 2 and 7 days post partum was investigated. Since biliary cirrhosis is a common occurrence in CF, hepatocytes in the treated mice were investigated by X-ray microanalysis and by light and electron microscopy. Treatment with amiloride caused a significant decrease in cellular Na concentration in adult animals and in in utero treated mice 2 days after birth. The decrease in Na was paralleled by a decrease in Cl, but K levels were not affected. Furosemide caused a slight increase of cellular Na concentrations, especially in animals aged 7 days. In the adult animals, both amiloride and furosemide caused a significant decrease of the cellular Na and Cl levels. No signs of cirrhosis could be observed. Inconsistent changes in the accumulation of lipid droplets in hepatocytes of adult animals treated with amiloride were observed by electron microscopy. It can be concluded that chronic treatment with diuretics, even though it causes some, possibly pathological, changes of the liver, is only of very limited value for generating an animal model to study liver disease in CF.