Nonenzymatic glucosylation of very-low density lipoprotein alters its metabolism in the rabbit.
In order to determine the metabolic consequences of lipoprotein glucosylation, the glucosylated 125I-VLDL turnover was analyzed in comparison to the native one. Autologous in vitro glucosylated VLDL, separated by affinity chromatography, was injected into a nondiabetic rabbit and the amount of the radioactivity distributed in all lipoprotein fractions measured. Glucosylated--125I-VLDL metabolism versus control--125I-VLDL after six hours were: glc-VLDL = 35 +/- 4.5%, control- VLDL = 35 +/- 4.9%, glc-IDL = 51 +/- 3.8% control-IDL = 31 +/- 4.3% p less than 0.01; glc-LDL = 9 +/- 2.2%, control-LDL = 12 +/- 2.6%; glc-HDL = 5 +/- 1.4%, control-HDL = 22 +/- 2.9% p less than 0.001. A retained turnover of glc-VLDL and prolonged retaining of the triglyceride-rich lipoproteins (VLDL, IDL) in the circulation were found. The results suggest that the incorporation of glucose into lipoproteins may influence the steric configuration of molecules by blocking the sites of the lipolytic action of lipoprotein lipase. The data presented provide strong support for the idea that there are factors other than reduced LPL activity which contribute to defective VLDL removal in diabetes mellitus.
Turk
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Z
Vuk Vrhovac Institute of Diabetes, Endocrinology and Metabolic Diseases, School of Medicine, University of Zagreb, Yugoslavia.
Skrabalo
Z
Z
D000818:Animals; D002846:Chromatography, Affinity; D017127:Glycation End Products, Advanced; D006031:Glycosylation; D007457:Iodine Radioisotopes; D007700:Kinetics; D008077:Lipoproteins, LDL / Q000097:blood; D008079:Lipoproteins, VLDL / Q000097:blood*; D011817:Rabbits; D000093844:Glycated Proteins
D017127:Glycation End Products, Advanced; D007457:Iodine Radioisotopes; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; C031797:glycated lipoproteins, LDL; D000093844:Glycated Proteins; C047671:glycated lipoproteins, VLDL