Clinica Chimica Acta 301 (2000) 119–134 www.elsevier.com / locate / clinchim Diminished rate of mouse peritoneal macrophage cholesterol efflux is not related to the degree of HDL glycation in diabetes mellitus ´ Marisa Passarelli, Alice F.M. Shimabukuro, Sergio Catanozi, Edna R. Nakandakare, Jussara C. Rocha, Alexandre J.F. Carrilho, * ˜ Eder C.R. Quintao ˜ ˜ Lipids Laboratory, University of Sao Paulo Medical School, Av. Dr. Arnaldo, 455 s /3317, Sao Paulo, Brazil Received 15 February 2000; received in revised form 15 June 2000; accepted 30 June 2000 Abstract 14 The efflux of C-cholesterol from mouse peritoneal macrophages mediated by in vivo and in vitro glycation of intact HDL and by HDL apolipoproteins was investigated. Cholesterol-laden 3 3 cells were incubated a long time with HDL from control subjects (C), poorly controlled diabetes 3 mellitus patients (D) and with HDL C submitted to in vitro glycation (G), as well as with all their respectively isolated apolipoproteins. A diminished cholesterol efflux rate occurred in incubations with intact HDL D but not with intact HDL G or with apoHDL C, G or D. The specific binding 3 3 3 125 of I-HDL G to the cell receptor, obtained upon incubation in the absence and in the presence of 3 excess unlabelled HDL , was lower than the control. The role of apoE secretion by cholesterol- 3 laden macrophages on cholesterol efflux was analyzed by incubating apoE knockout and control mice macrophages with HDL C or HDL G: a lower cholesterol efflux was observed from apoE knockout macrophages but glycation of HDL did not influence this process either. The 3 diminished capacity to remove cholesterol by the HDL drawn from diabetic subjects must be attributed to other modifications of the lipoproteins, except for non enzymatic glycation. Thus, Abbreviations: LP, lipoprotein; HDL, high density lipoprotein; LDL, low density lipoprotein; C, normal control; G, glycated; D, diabetic; TNBS, trinitrobenzenesulfonic acid; TBARS, thiobarbituric acid reactive substances; RCT, reverse cholesterol transport; LCAT, lecithin cholesterol acyltransferase; CETP, cholesterol ester transfer protein; ACAT, acyl cholesterol acyltransferase; NHCE, neutral hydrolase cholesteryl ester; KO apoE, knockout apoE *Corresponding author. Tel.: 1 55-11-3062-1255; fax: 1 55-11-3062-1255. ˜ E-mail address: lipideq@usp.br (E.C.R. Quintao). 0009-8981 / 00 / $ – see front matter  2000 Elsevier Science B.V. All rights reserved. PII: S0009-8981(00)00336-3