Iron ions effect on lipid peroxidation in model membranes an on mitochondrial activity of CHO cells.

FAGALI, N.; GRILLO, C; CATALÁ, A.; PUNTARULO, S; FERNANDEZ LORENZO DE MELE, M.

Mendoza

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2012

SAIB

We have attempted to gain understanding of the mechanisms responsible for lipid peroxidation (LP) in a simple model system, made by dispersing retinal lipids in the form of liposomes (Ls). Although LP in model membranes may be very different from that in biological membranes, the results obtained in the former may be useful to get information about processes in the more complex biological environment. In spite of the relative simplicity of LP of Ls, these reactions are still relatively complex because they depend on many factors like liposome type, reaction initiator and reaction medium. Here we describe: a) a method to prepare small Ls with natural phospholipids and b) the results obtained by the analytical techniques (DLS, TBARS production, determination of conjugated dienes production and analysis of fatty acid profile by CG-MS) used to follow LP initiated by iron ions in these Ls. Results show that Fe+2 ions were more efficient initiators than Fe+3. The effect of iron ions was also investigated in CHO-K1 cell cultures. As tested by MTT assay, a significant reduction (p < 0,001) in mitochondrial activity to 80% of the control value was observed for Fe+2 1 mM decreasing to 61% in the case of 4 mM. A significant reduction (p < 0,001) in mitochondrial activity to 86% of the control value was observed for Fe+3 1 mM decreasing to 63% in the case of 4 mM.