Alterations in Lipoprotein Composition Associated with Carbon Tetrachloride-Induced Rat Liver Injury

Abstract

To investigate alterations in lipoprotein composition associated with carbon tetrachloride-induced rat liver injury, electrophoretic patterns of rat apoproteins were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and compared with those in man. Rat apoprotein (apo) A-I and apo E were shown to migrate the same distances as those of man, though rat apo A-II + apo C-II and apo C-III migrated farther. Administration of 1.0 mi/kg CCl₄ decreased the lipid contents, the very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL) fractions in the serum. Transaminase activity and total protein (TP) content increased with increased CCl4 administration. The percentage of albumin nonesterified fatty acid (Alb-NEFA) increased and HDL₂ fraction decreased. Administration of 1.0 ml/kg CCl₄ decreased apo C-I and apo E in the HDL fraction. The bands of apo A-I, apo A-II, apo A-II + apo C-II and apo E in the HDL fraction declined after 2.0 ml/kg CCl₄ administration. Apoproteins in the VLDL+LDL fraction appeared to decrease after CCl₄ treatment. It was suggested that lipoprotein abnormalities induced by CCl₄ application may be related to inhibition of apoprotein synthesis, suppression of lipoprotein lipase activity, and the decline of HDL₂.