STREPTOZOTOCIN-INDUCED AND ALLOXAN-INDUCED DIABETES MODIFIES TOTAL PLASMA AND LIPOPROTEIN LIPID-CONCENTRATION AND COMPOSITION WITHOUT ALTERING CHOLESTERYL ESTER TRANSFER ACTIVITY

The objectives of this study were to determine the total plasma and li poprotein lipid concentration and composition and cholesteryl ester tr ansfer activity in two diabetic animal models (alloxan-induced diabete s in rabbits and streptozotocin-induced diabetes in rats). Furthermore , we wanted to determine if the severity of diabetes influences lipopr otein lipid profiles and cholesteryl eater transfer activity. Rats and rabbits were randomly divided into non-diabetic and diabetic groups. Rats were administered either 55 mg/kg or 100 mg/kg of streptozotocin intravenously through the tail vein, while rabbits were administered 1 00 mg/kg or 200 mg/kg of alloxan intravenously through the marginal ea r vein under light anesthesia. Hyperglycaemia was tested for at 48 hr following the doses. Total and lipoprotein cholesterol and triglycerid e concentrations using enzymatic kits and cholesteryl ester transfer a ctivity from low-density lipoproteins to high-density lipoproteins usi ng H-3-cholesteryl ester incorporated into low density lipoproteins we re determined. Elevations in both total and lipoprotein cholesterol an d triglyceride concentrations and alterations in lipoprotein lipid com position are observed following the onset of drug-induced diabetes in rats and rabbits compared to non-diabetics. However, these findings we re observed only in animals administered the higher streptozotocin and alloxan dose. Furthermore, cholesteryl ester transfer from low-densit y lipoproteins to high-density lipoproteins is not significantly diffe rent in drug-induced diabetic compared to non-diabetic rats and rabbit s, regardless of which streptozotocin and alloxan dose was used. These findings suggest that difference in lipoprotein lipid concentration a nd composition as a result of drug-induced diabetes is independent of cholesteryl ester transfer activity in both rats and rabbits. Furtherm ore, diabetic severity may influence lipoprotein metabolism in these a nimal models.