Morphologic changes in livers of hamsters treated with high doses of ursodeoxycholic acid: correlation with bile acids in bile.

The effects of high doses of ursodeoxycholic acid on bile acid composition and the liver morphology was examined in 60 male Syrian golden hamsters. The animals were allocated to five groups: I, control; II and IV received 0.5 g and 1 g of ursodeoxycholic acid per 100 g of standard diet respectively over 30 days and III and V received 0.5 g and 1 g of ursodeoxycholic acid per 100 g of standard diet respectively over 60 days. Bile acids were determined by high performance liquid chromatography. In all treated groups there was a significant increase in chenodeoxycholic and lithocholic acid in the bile. The mean glyco/tauro ratio was significantly higher than in the control group, reaching values > 1 for individual bile acids, except for lithocholic acid values which remained < 1. Under light microscopy, the livers of the hamsters showed damage which was dose/time related, namely portal inflammatory infiltrate, bile duct proliferation, cholestasis, fat infiltration and necrosis. Electron microscopy revealed pronounced changes starting with microvilli edema and extending to canalicular membrane destruction and necrosis. The changes observed in the relation glyco/tauro lithocholic acids, may be due to defence mechanisms to avoid hepatotoxicity. The hepatotoxicity resulting from ursodeoxycholic acid administration is presumed to be due primarily to lithocholic acid or some lithocholic acid metabolite.

Consumption coagulopathy in acute renal failure induced by hypolipotropic diets.

Weanling male rats fed on a hypolipotropic diet develop acute renal failure whose morphological features vary from focal tubular necrosis to cortical necrosis. We have sequentially studied the hemostatic mechanism in correlation with the morphology of various tissues, mainly renal and hepatic, in choline-deficient rats as well as in three control groups. No important changes were observed in the hemostatic mechanisms before the development of tubular necrosis. Along with tubular necrosis a consumption coagulopathy was found, evidenced mainly by a decrease in the activity of factors V and VIII as well as a prolongation in PTTK and Quick's time and a decrease in platelets. Fibrin degradation products were found in serum and urine and soluble fibrin monomer complexes in the former. Following tubular necrosis thrombi were found in the renal microvasculature. It is possible to speculate that the tubular necrosis induced by choline deficiency could produce an activation of the coagulation system which in turn would lead to thrombosis of the renal microcirculation and cortical necrosis.