Journal of Lipid Research, Vol 31, 137-147, Copyright © 1990 by Lipid Research, Inc.

ARTICLES

Lipolysis of menhaden oil triacylglycerols and the corresponding fatty acid alkyl esters by pancreatic lipase in vitro: a reexamination

LY Yang, A Kuksis and JJ Myher
Banting and Best Department of Medical Research, Toronto, Canada.

In order to distinguish between possible fatty acid differences during lumenal lipolysis and cellular absorption, we have reinvestigated the in vitro hydrolysis of menhaden oil and its alkyl esters by pancreatic lipase. For this purpose we incubated menhaden oil or its fatty acid methyl and ethyl esters with porcine pancreatic lipase in the presence of bile salts and determined the composition of the released free fatty acids, monoacylglycerols, diacylglycerols, and residual triacylglycerols, or the free fatty acids and residual alkyl esters, respectively, by thin-layer and gas-liquid chromatography. There was significant discrimination against the delta 4- to delta 7-unsaturated fatty acids of both medium and long chain lengths during the hydrolysis of menhaden oil and its fatty acid ethyl esters. In general, the ethyl esters were hydrolyzed 10-50 times more slowly than the corresponding glyceryl esters, depending on the exact ratio of the two substrate types. None of the triacylglycerols or ethyl esters, however, was completely resistant to hydrolysis resulting in an eventual cleavage of all the alkyl esters and presumably all the primary ester bonds in the triacylglycerol molecules. Since the rate of release of the least resistant fatty acid exceeded that of the most resistant acid by only a factor of 6, it is concluded that in the presence of a large excess of lipase the liberated fatty acids would approach the composition of the dietary alkyl or glyceryl esters, as observed during lumenal lipolysis (Yang, L.-Y., A. Kuksis, and J. J. Myher. 1989. Biochem. Cell Biol. 67: 192-204).
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. E. Lowe The triglyceride lipases of the pancreas J. Lipid Res., December 1, 2002; 43(12): 2007 - 2016. [Abstract] [Full Text] [PDF]

				L. Zhou and A. Nilsson Sources of eicosanoid precursor fatty acid pools in tissues J. Lipid Res., October 1, 2001; 42(10): 1521 - 1542. [Abstract] [Full Text] [PDF]

				J.-C. Martin, J.-L. Sébédio, C. Caselli, C. Pimont, L. Martine, and A. Bernard Lymphatic Delivery and In Vitro Pancreatic Lipase Hydrolysis of Glycerol Esters of Conjugated Linoleic Acids in Rats J. Nutr., May 1, 2000; 130(5): 1108 - 1114. [Abstract] [Full Text]

				M. E. Lowe Molecular Mechanisms of Rat and Human Pancreatic Triglyceride Lipases J. Nutr., April 1, 1997; 127(4): 549 - 557. [Abstract] [Full Text]