Acta bioquímica clínica latinoamericana
versión On-line ISSN 1851-6114
DE MARCO, Catalina Beatriz et al. In vitro glycation of low-density lipoproteins and atherogenicity in cell culture. Acta bioquím. clín. latinoam. [online]. 2007, vol.41, n.3, pp. 337-346. ISSN 1851-6114.
Long-term hyperglycemia increases protein glycation. In particular, modifications in the low-density lipoproteins (LDL) increase their atherogenic potential. In this study, the modifications caused by in vitro glycation of LDL separated by two methods: selective precipitation (SP) and ultracentrifugation (UC) were compared. Increase fructosamine level, decrease of e-amino group of lysine, guanidinio of arginine and triptophan fluorescence were determined. Results showed significant differences vs. basal (p<0.05) for all the tested parameters, with coincidence for the two separation methods both in time and grade of modifications. The atherogenicity of glycated LDL separated by SP was studied in macrophages RAW 264.7 in culture, through the formation of foam cells and the quantification of the dye taken up by the cellular storage lipids. Results show that the uptake of modified LDL by macrophages increased with the time of incubation, being the atherogenicity of glycated LDL greater than native LDL (p<0.001, 1 h at 37 °C). The selected SP procedure, within the facilities of routine biochemical laboratory, enables the evaluation of the modifications caused by glycation in the LDL of diabetic patients.
Palabras llave : glycation; low density lipoproteins; selective precipitation of low density lipoproteins; atherogenicity; macrophages.