SUSCEPTIBILITY TO IN-VITRO LIPID-PEROXIDATION OF LOW-DENSITY LIPOPROTEINS AND ERYTHROCYTE-MEMBRANES FROM LIVER CIRRHOTIC-PATIENTS

The aim of the present study was to investigate the susceptibility of low density lipoprotein (LDL) and red blood cell membranes (RCM) from liver cirrhotic patients and control subjects, to the peroxidative str ess, induced in vitro by phenylhydrazine. The susceptibility to peroxi dation was determined by measuring the formation of the thiobarbituric acid reactive substances (TBARS) after incubation with phenylhydrazin e. Moreover the levels of cholesterol (C) and phospholipid (PL) were e valuated in plasma and isolated LDL and RCM. A significant decrease in plasma C, LDL-C and RCM-C content (p < 0.001, p < 0.01 and p < 0.05 r espectively) and RCM-PL content (p < 0.01) were found in cirrhotic pat ients compared to controls. The lower susceptibility to in vitro perox idation was shown by the TBARS levels significantly lower in LDL and R CM from cirrhotic patients with respect to controls (p < 0.0001 for bo th of them). Moreover significant positive correlations were found bet ween TBARS-LDL and LDL-C or LDL-PL (r = +0.72, p < 0.0001; r = +0.58, p < 0.001) and between TBARS-RCM and RCM-C (r = +0.35, p < 0.05) or RC M-PL (r = 0.37, p < 0.05) from combined patients and controls. Our dat a seem to ascribe the lower in vitro peroxidability to the lower level s of plasma lipids.