XI International Symposium on
DRUGS AFFECTING LIPID METABOLISM
Florence (Italy), May 13-16, 1992
INCREASE OF APO A1 CONCENTRATION IN HYPERCHOLESTERAEMIC CHICKENS AFTER TREATMENT WITH A NEWLY DEVELOPED EXTRACORPOREAL LIPID ELIMINATION.
K. KOSTNER, B. CHAM, A. DWIVEDY, T. SHAFEY and N. X.FANG
Dept. Medicine, Uni of Qld, Brisbane, Australia.
Four groups of 5 roosters were used in this study. Hyperlipidaemia and atherosclerosis were induced in two groups by feeding them a diet high in cholesterol and by injection of oestradiol benzoate. Plasma cholesterol concentration increased by a factor of 8 and triglycerides concentration by a factor of 50 in the estrogenized birds. The other two groups served as normolipidaemic controls. A newly developed delipidation procedure termed " cholesterol-apheresis" (CA) was applied 5 times during the six weeks experimental period to one group of the normolipidaemic and one group of the hyperlipidaemic birds. CA consisted of the removal of 25% of the blood volume, separation of red blood cells ( RBC ) and delipidation of plasma by a solvent mixture of Butanol and Diisopropyl ether. The delipidated plasma was mixed with the RBC and reinjected into the birds. I Delipidadon removed all neutral lipids and approximately 50% of phospholipids. CA reduced plasma total cholesterol and triglycerides. Increases in plasma lecithin cholesterol acyl transferase activity and cholesterol ester concentration were observed. Plasma APO AI concentrations increased approximately 80% in both the treated hypercholesteraemic and the normocholesteraamic birds. Interestingly the APO A1 concentration increased to a higher extent than the HDL concentration. In both control birds no increase of the APO AI concentration was found. Haematological and biochemical parameters in the birds were not affected. Postmortem examination of the aorta revealed rapid regression of atherosclerosis. These preliminary results indicate that CA accelerates reverse cholesterol transport in an avian model. It will be interesting to see if this phenomenon will also be applicable to mammals.