Hydrolysis of triacylglycerol arachidonic and linoleic acid ester bonds by human pancreatic lipase and carboxyl ester lipase

• The hydrolysis of polyenoic fatty acid ester bonds with pure human colipase-dependent lipase, with carboxyl ester lipase (CEL) and with these enzymes in combination was studied, using [3H]arachidonic- and [14C]linoleic acid-labelled rat chylomicrons as a model substrate. During the hydrolysis with colipase-dependent lipase, the amount of 3H appearing in 1,2-X-diacylglycerol (DG) markedly exceeded that of 14C. When CEL was added in addition this [3H]DG was efficiently hydrolyzed. CEL alone hydrolyzed the triacylglycerol (TG) at a low rate. The hydrolysis pattern with human duodenal content was similar to that seen with colipase-dependent lipase and CEL in combination. Increasing the concentration of taurodeoxycholate (TDC) and taurocholate (TC) or of TDC alone stimulated the hydrolysis of [3H]- and [14C]TG, but increased the accumulation of labelled DG that could act as substrate for CEL. It is suggested that very-long-chain polyenoic fatty acids of DG formed during the action of the colipase-dependent lipase on TG containing these fatty acids may be a physiological substrate for CEL.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Andra medicinska och farmaceutiska grundvetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Other Basic Medicine (hsv//eng)

Nyckelord

Arachidonic Acid

Arachidonic Acids/metabolism

Bile Acids and Salts/pharmacology

Carboxylesterase

Carboxylic Ester Hydrolases/physiology

Chylomicrons/metabolism

Humans

Hydrolysis

In Vitro Techniques

Linoleic Acid

Linoleic Acids/metabolism

Lipase/physiology

Pancreas/enzymology

Time Factors

Triglycerides/metabolism

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)