Histopathological Changes in Organs of New Zealand White Rabbits Following Dichlorvos Exposure

Aim: To assess the changes in histological indices in the organs of New zealand white rabbits treated with 2, 2- dichlorovinyl dimethyl phosphate.

Study Design: This is an experimental study.

Methodology: A total of twenty four male New Zealand white rabbits, two months old weighing between 1.0 and 1.2 kg, were used for the study. They were divided into three (3) groups, each consisting of four (4) rabbits and a corresponding number of matched controls, for long-term toxicological effects of dichlorvos on the rabbits (30 days, 60 days and 90 days). The rabbits received ten percent (10%) of the LD50 dose . The LD50 dose was 0.05 mg/m3, while 10% of the median lethal dose of dichlorvos which was 0.005 mg/dl was diluted with 1.0 milliliter of distilled water. It was administered by oral route daily for the stipulated periods of thirty, sixty, and ninety days. At the end of each month, a set of rabbits in the experimental group with their matched control were sacrificed using chloroform. Organs of the liver, kidney, heart, and lungs were harvested from the rabbits at the stipulated period of thirty, sixty, and ninety days with their matched controls and were preserved in 10% formalin for histological examinations.

Results: Examination of organ tissues revealed alterations which depended on the duration of dichlorvos exposure. The kidney slide showed tubular necrosis; heart tissues showed degeneration of myocardial fibers with congestion of blood vessels; liver tissues revealed gross hepatic necrosis, while the lungs tissues revealed area on inflammatory cell infiltrates and alveolar oedema when compared with their matched controls at 30, 60 and 90 days.

Conclusion: Examination of tissues of the heart, lungs, liver and kidneys revealed pathological changes on the dichlorvos treated rabbits when compared with their matched controls.