Increased lipolytic activity of sera from pre-eclamptic women due to the presence of a lysophospholipase

Abstract

Endresen MJ, Lorentzen B, Henriksen T. Increased lipolytic activity of sera from pre-eclamptic women due to the presence of a lysophospholipase. Scand J Clin Lab Invest 1993; 53: 733-739.

Sera from pre-eclamptic women exhibit an increased lipolytic activity compared to sera of women with normal pregnancies. The null hypothesis of this study was that the increased release of free fatty acids (FFA) was due to hydrolysis of circulating triglycerides. The nature of the increased lipolytic activity was investigated by incubating sera from pre-eclamptic (PE) and normal pregnant women (C) with various lipid substrates radiolabeled in the FFA position.

The release of FFA in PE-sera was not due to hydrolysis of triglycerides or diglycerides. Lysophosphatidylcholine, however, served as substrate for the enhanced lipolytic activity. By using lysophosphatidylcholine with radiolabeled FFA in the sn-1-position we found that 32±10nmol FFAml^_1h^_1 was released in PE-sera, compared to 10±4nmol FFAmP'h⁻¹ in C-sera. This lysophospholipase activity appears independent of Ca²⁺ and other divalent cations. The increased release of FFA in sera of pre-eclamptic women can be explained by the presence of a lysophospholipase which releases the remaining fatty acid of lysophosphatidylcholine.

Key Words:

• endothelium
• free fatty acids
• phospholipases
• pre-eclampsia