Cholesterol removal by peritoneal lavage with phospholipid-HDL apoprotein mixtures in hypercholesterolemic hamsters

Syrian hamsters were rendered hypercholesterolemic by supplementation of their diet with 1% cholesterol and 15% butter. The hamsters were injected intraperitoneally (i.p.) with about 20 mg of phospholipid liposomes containing trace amounts of 3H]cholesteryl linoleyl ether ( 3H]CLE) alone or combined with 10 mg delipidated high-density lipoprotein (apoHDL). After 2 h the peritoneal cavity was washed repeatedly with up to 15 ml phosphate-buffered saline. 60%-70% of 3H]CLE were retained after i.p. injection without apoHDL, 30-50% in the presence of apoHDL. The amount of free cholesterol recovered in the peritoneal lavage was significantly higher when apoHDL was combined with 18:2 sphingomyelin or dilinoleyl phosphatidylcholine liposomes, when compared to either liposomes or apoHDL alone. It is suggested that supplementation of dialysate with HDL apolipoproteins and phospholipids in patients undergoing continuous peritoneal dialysis could be of use in a cholesterol depletion regimen.