Dimethoate-induced lipid peroxidation in Leydig cell is reverted by in vitro tocopherol addition.

HURTADO DE CATALFO GRACIELA; ASTIZ MARIANA; TACCONI DE ALANIZ MARÍA J.; MARRA CARLOS ALBERTO

Villa Carlos Paz, Córdoba.

Congreso; XLIV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB).; 2008

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

    Dimethoate (D) is involved in deleterious effects on testicular physiology. We studied the impact of a sub-chronic administration of D to Wistar rats (15 mg/Kg body weight ip, 5 weeks) on the neutral (N) and polar (P) lipid composition, antioxidant status and peroxidability of microsomal (Mi) and mitochondrial (Mt) membranes isolated from Leydig cells. N and P fatty acyl chains from Mi membranes were enriched in PUFAs compared with Mt fraction. D treatment did not modify their composition; however, it produced a significant decrease in the tocopherol (Toc) content. The loss of Toc correlated with both an increased TBARS production, and a high sensitivity to peroxidation (PX). The time-curse of the in vitro t-BHP-induced PX was measured as TBARS generation under standard incubation conditions. At zero time, membranes isolated from D-treated rats showed an increase of TBARS. The lag of induction almost disappeared in cells isolated form intoxicated animals and the rate of propagation and the maximal production of TBARS were significantly increased. These alterations were almost reverted by in vitro Toc addition. The protective effect was dose-dependent and followed a sigmoidal behavior. Toc may be effective in the protection of Mi and Mt membranes of Dintoxicated cells and in the preservation of PUFAs intimately involved in androgenic function and spermatogenesis.