PURPOSE: The aim of the present study was to investigate the effects of diazinon and propoxur on liver and kidneys, following long term exposure of rabbits.METHODS: Ten New Zealand white female rabbits were used. The animals were divided into 5 groups, consisting of 2 animals each. Diazinon (groups 1 and 2) and propoxur (groups 3 and 4) were administered at 2 different doses, and group 5 served as the control group. Histopathological lesions in the liver and kidneys, oxidative stress and oxidative DNA damage were evaluated.RESULTS: Both pesticides induced focal inflammation and fibrosis in the liver and kidneys. The low dose of propoxur induced a significant increase in total antioxidant capacity (TAC), with no difference in reduced glutathione (GSH), while the high dose of propoxur induced an increase in GSH with no change in TAC. For diazinon-exposed animals, the opposite findings were observed. Both diazinon and propoxur induced a statistically significant oxidative DNA damage in the liver and kidneys and a subsequent increase in telomerase activity in these tissues, possibly as a counteracting mechanism. Furthermore, systemic inflammation, as depicted by the dose-dependent increase in telomerase activity in peripheral blood mononuclear cells (PBMCs), was observed in propoxur treated animals.CONCLUSIONS: Histopathological lesions, oxidative stress and genotoxic effects were induced in liver and kidneys following long term exposure of rabbits to diazinon and propoxur.