Effects of unsaturated fatty acids in phospholipids on the in vitro activation of the lipoprotein lipase and the triglyceride lipase.

The effects of different types of phospholipids on the lipoprotein lipase (LPL) and on the hepatic triglyceride lipase (TGLH) were studied by comparative in vitro incubation. Substrates were prepared by homogenization in glycerol of 3H-labelled triolein plus phosphatidylcholine (either dipalmitoyl PC, or ovolecithin or highly unsaturated PC, EPL Nattermann). Enzymes were obtained from rat adipose tissue, myocardium, lungs and liver and human adipose tissue and post-heparin plasma, respectively. The enzyme activities as determined in mmol/ml medium showed differences of highly statistical significance (p less than 0.001). In any tissue investigated the enzyme activities of LPL or TGLH followed the sequence: highly unsaturated PC (EPL) greater than ovo-lecithin greater than dipalmitoyl-lecithin. This was true for the enzymes of rat and human origin as well. It was concluded that the observed LPL and TGLH activation may account for the beneficial therapeutic effects of highly unsaturated phosphatidylcholine (EPL) in human hyperglyceridemias.