Testicular steroidogenesis in rats intoxicated with dimethoate, zineb of glyphosate.

ASTIZ MARIANA; HURTADO DE CATALFO GRACIELA; ALANIZ MARIA J.T. DE; MARRA CARLOS ALBERTO

Mar del Plata, Buenos Aires, Argentina

Congreso; SAIB 43 th Annual Meeting; 2007

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Previous experiments demonstrated that pesticides significantly modify the redox homeostasis of testis. We studied the biosynthesis of testosterone (T) in testis from Wistar rats chronically intoxicated by i.p. injection of dimetoathe (D), zineb (Z) or glyphosate (G) (1/50 to 1/250 DL50 three times a week for 5 weeks). In all groups that received D the level of T (free or bound) was decreased compared to control values. This effect was augmented by association with G o Z. Concomitantly, plasma concentrations of LH and FSH were increased and estradiol level simultaneously decreased. Concentration of T was also decreased in testicular homogenates. These hormonal changes were directly related with increments in the production of [NOx], ROOHs, total glutathione, protein carbonyls, and protein thiols. Total antioxidant capacity (FRAP) and a-tocopherol content were diminished in intoxicated rats. The activities of the androgenic enzymes 3b-HSD and 17b-HSD were decreased slightly in rats treated with G, but they were strongly inhibited in those groups receiving D (alone or in combination with G or Z). In a separate study we demonstrated that hidroxyesteroid deshydrogenases were inhibited by overproduction of ROS. Thus, we conclude that organophosphorated pesticides (especially D) decreased the biosynthesis of T through a mechanism that involved reactive oxygen species and subsequent damage of the two key androgenic enzymes. This conclusion may be relevant in monitoring steroidogenic function in man professionally exposed to this kind of pesticides.