LECITHIN:CHOLESTEROL ACYLTRANSFERASE KINETICS IN SERUM OF NEW ZEALAND WHITE RABBITS
Abdullah Madany, Ronald Tan, Cindy Barlan, Aileen Ariosa and Raymond E. Garcia
Abstract: New Zealand White (NZW) rabbits, like humans, develop hypercholesterolemia when fed cholesterol-rich diets, resulting in the premature development of cardiovascular disease (CVD). Lecithin:cholesterol acyltransferase (LCAT) is the enzyme that is responsible for the synthesis of cholesteryl esters in the blood and is a key player in reverse cholesterol transport (RCT). Theoretically, an active LCAT stimulates RCT, which reduces the risk of CVD. The overall goal of this project is to understand the molecular mechanisms by which an active LCAT activity protects against the development of CVD and the role of jojoba oil in this process. It is our hypothesis that dietary jojoba oil stimulates LCAT in hypercholesterolemic NZW rabbits. To test this hypothesis, NZW rabbits were fed either a normal (N), 3% jojoba oil (J), 1% cholesterol (C), or 1% cholesterol + 3% jojoba oil diet. Blood was collected at 0 and 7 days and was allowed to clot, after which serum was obtained by centrifugation. The concentration of free cholesterol (FC) was measured with an enzymatic assay. The rate of LCAT (cholesterol esterification rate) was found by measuring the disappearance of FC concentration over time. The results indicate that the rate of esterification of FC by LCAT increases when jojoba oil is supplemented to the cholesterol-rich diet. Future studies will determine if this increased LCAT rate lowers the risk of CVD.