Regulation of 3-hydroxy-3-methylglutaryl-coenzyme A Reductase in Rat Liver and Morris Hepatomas 5123C, 9618A and 5123t.c
Overview
Authors
Affiliations
Characteristics of 3-hydroxy-3-methylglutaryl-CoA reductase from normal liver, Morris hepatomas 5123C, 5123t.c. and 9618A, and host liver were studied. Animals were fed on control and 5%-cholesterol diets. Microsomal membranes from all tissues were found to accumulate cholesterol after 3 days on the 5%-cholesterol diet. The enzyme of the tumours showed no feedback inhibition by dietary cholesterol, and that of host liver gave a variable response, whereas that of control liver was constantly inhibited by 90% or more. Arrhenius-plot analysis was conducted on the microsomal enzyme isolated from the various tissues. Control animals showed that the phase transition present at 27 degrees C was removed when animals were fed on 5%-cholesterol diet for 12 h. The hepatomas failed to show this change even after 3 days of 5%-cholesterol diet and a significant increase in microsomal cholesterol. This failure to remove the break in Arrhenius plots also occurred in host liver, even though enzyme inhibition occurred. The reason why hepatomas fail to regulate 3-hydroxy-3-methylglutaryl-CoA reductase activity in response to dietary cholesterol may be a decreased membrane-enzyme interaction.
Hashemi S, Bathaie S, Mohagheghi M Avicenna J Phytomed. 2020; 10(4):384-397.
PMID: 32850295 PMC: 7430959.
Cruz P, Mo H, McConathy W, Sabnis N, Lacko A Front Pharmacol. 2013; 4:119.
PMID: 24093019 PMC: 3782849. DOI: 10.3389/fphar.2013.00119.
Simvastatin stimulates apoptosis in cholangiocarcinoma by inhibition of Rac1 activity.
Miller T, Yang F, Wise C, Meng F, Priester S, Munshi M Dig Liver Dis. 2011; 43(5):395-403.
PMID: 21334995 PMC: 3071437. DOI: 10.1016/j.dld.2011.01.010.
Barnard G, Erickson S, Cooper A J Clin Invest. 1984; 74(1):173-84.
PMID: 6330173 PMC: 425198. DOI: 10.1172/JCI111399.
Maltese W, Defendini R, Green R, Sheridan K, Donley D J Clin Invest. 1985; 76(5):1748-54.
PMID: 3850904 PMC: 424200. DOI: 10.1172/JCI112165.