The fatty acid composition of lipids extracted from plasma membranes of spontaneous mouse mammary gland carcinomas

No Thumbnail Available
Authors
Rednour, Thomas L., 1949-
Advisor
Bennett, Alice S.
Issue Date
1975
Keyword
Degree
Thesis (M.S.)
Department
Other Identifiers
Abstract

The purpose of this research was to determine the fatty acid composition of lipids as compared to those of normal tissue. The altered molecular structure of these lipids could cause changes in the plasma membrane fluidity and membrane integrity producing the membrane characteristics associated with carcinomas.Plasma membranes-were isolated by differential centrifugation from both tumor and normal tissue from Strong A female mice. The lipids were extracted, separated by thin-layer chromatography, saponified and the fatty acid methyl esters identified and quantified by gas chromatography. The lipids were separated into four classes, cholesterol esters, triglycerides, free fatty acids and phospholipids. The carcinoma samples exhibited a reduction in the fatty acids of 10 to 14, carbons in chain length by as much as 32 percent. The level of palmitic acid increased in the tumor fractions as much as double the normal amount. The level of palmitoleic acid also increased in the tumor fractions nearly proportional to the palmitic acid. The stearic acid content in the tumor fractions increased as did the oleic acid in three of the four lipid classes, again nearly proportional to the stearic acid. Levels as high as 29 percent of henicosanoic acid in some normal tissue samples were found, but the carcinoma samples exhibited no higher than 10 percent. The increased production of heptadecadienoic acid in the carcinoma fractions along with the appearance of eicosatrienoic acid when only low scattered amounts were found in the normal fractions indicated that a shift in fatty acid biosynthesis has occurred, it would appear that in the carcinoma, the biosynthetic pathway for synthesis of fatty acids in the plasma membranes shifted from a de novo to a chain elongation pathway as the principal route.

Collections