Zonal differences in lipoprotein formation in the thioacetamide-induced micronodular-cirrhotic rat liver.

The aim of the studies was to answer the question to what extent thioacetamide-induced structural alterations of hepatic architecture leading to fibrosis and micronodular pseudolobuli affect the formation of very low density lipoproteins and the zonation of lipoprotein metabolism observed in normal and acutely injured livers. Therefore, the number of the VLDL particles/Golgi complex and the relative specific volume of Golgi complexes as well as the number and relative specific volume of VLDL-filled vesicles was determined in lobular and nodular zones of normal and the micronodular-cirrhotic livers, respectively. The perinodular and centrinodular regions were morphometrically analysed in nodules with diameters between 0.3 and 0.5 mm. -Generally, in thioacetamide-induced micronodular liver cirrhosis a zonality was observed with respect to the amount of VLDL particles as well as the number and volume of organelles involved in the formation and secretion of hepatic lipoproteins. However, the number of VLDL particles/Golgi complex was significantly reduced to 52% in the centrinodular and to 71% in the perinodular region of cirrhotic livers when compared with the corresponding periportal and perivenous area, respectively. Furthermore, the relative specific volume of the Golgi complexes markedly increased in the perinodular region, thus abolishing the zonal difference observed in the controls.(ABSTRACT TRUNCATED AT 250 WORDS)