Abstract

GLYCATION BY GLUCOSE AND KETONE BODIES OF AMINOPHOSPHOLIPIDS FROM HUMAN TISSUES IS INHIBITED BY L-ARGININE AND CREATINE. II. AORTA ARTERY

José D. Méndez*, Adolfo Chávez-Negrete and Guillermo Valero

Abstract

β-Hydroxybutyrate and acetoacetate are an alternative source of energy for several tissues and organs including the heart. However, large quantities are found in the blood in type 1 and type 2 diabetics with poor metabolic control. High concentrations of ketone bodies are associated with diabetic ketoacidosis. The involvement of ketone bodies in the glycation of bovine hemoglobin and rat brain aminophospholipids has been demonstrated. In this study the effect of L-arginine and creatine on the glycation of human aortic aminophospholipids by glucose and ketone bodies was evaluated. Aminophospholipids were isolated and their purity confirmed by thin layer chromatography. Emulsions were prepared in 0.1 M phosphate buffer, pH 7.4 containing 11 mM glucose, 3 mM β-hydroxybutyrate or 3 mM acetoacetate, respectively. When the effect of L-arginine or creatine was tested, 10 mM concentration was used. Emulsions were prepared and incubated at 37 °C in dark during 61 days. Samples were taken on days 0, 12, 19, 26, 48 and 61. Then, they were analyzed by thin layer chromatography, fluorescence and ultraviolet spectroscopy. Three spots with Rf of 0.12, 0.17, and 0.244, respectively, showed higher intensity. However, several spots with lower intensity were also revealed. Glycation of aminophospholipids was clear. It was higher for glucose followed by β-hydroxybutyrate and acetoacetate. Seen by three ways; thin layer chromatography, fluorescence and ultraviolet spectroscopy, both L-arginine and creatine affected glycation process. The effect of L-arginine was clear in mixtures containing aminophospholipids, glucose and β-hydroxybutyrate. Less relative fluorescence was observed when creatine was added to mixtures containing acetoacetate. The spectral signals in the ultraviolet region (290 to 200 nm) suggest the formation of several compounds between aminophospholipids, glucose and ketone bodies. In conclusion, these results provide evidence that aortic aminophospholipids are affected not only by high concentrations of glucose but also by ketone bodies. Since glycation has been associated with the development of cardiovascular disease, this process can be prevented with L-arginine and creatine.

Keywords: Acetoacetate, Aminophospholipids, L-Arginine, Creatine, Glycation, Human aorta, ?- Hydroxybutyrate, Hyperglycemia.