The Role of Membrane Composition in ATPase Activities of Cirrhotic Rat Liver: Effect of Silymarin
Journal/Book: Journal of Applied Toxicology. 1990; 10: 281-284.
Abstract: The activities of Ca2+- and Na+, K+-ATPases were studied in liver plasma membranes from CC14-cirrhotic rats and from livers of rats treated with silymarin in addition to CCI4,. CC14 chronic treatment produced significant decreases in Na+, K+- and Ca2+-ATPase activities; however, the animals treated with silymarin along with CCI4showed no differences in ATPase activities as compared to controls. The lipid analysis performed in plasma membranes revealed increases in the cholesterol/phospholipid (CH/PL) and sphingomyelin/phosphatidylcholine (SNI/PC) ratios in the cirrhotic group. Again, the membranes isolated from rats receiving CCI4, + silymarin showed normal CII/PL and SNI/I'C values. Considering that CH/PL and SNI/PC ratios are related to membrane microviscosity, this study suggests that a lower fluidity of the membrane may be responsible for the observed decreases in ATPase activities in the cirrhotic group. Additionally, the role of silymarin to improve liver function in CCI4-cirrhosis can be attributed partially to its action at membrane level by preventing the increases in CII/PL and SNI/PC ratios.