Alexandria Journal of Veterinary Sciences www.alexjvs.com AJVS. Vol. 54 (1): 82-99. Jul. 2017 DOI: 10.5455/ajvs.269380 Protecting Role of Selenium on the Cytotoxic Effect of Profenofos on Rabbit Fertility Ghada, H. Abdel-Rahman 1 , Abeer, E. El-Metwally 2 , Hanaa A. El-Hallawany 3 and Amal H. Ali 4 1 Biology Dept.; 2 Pathology Dept., Animal Reproduction Research Institute (A.R.R.I.) and 3 National Research Center, (N.R.C.) Abstract Key words: Profenofos – Histopathology- Caspase- 3 –Biochemical- Hormones- Antioxidants- Reproductive toxicity – Selenium- Liver - kidneys - Rabbits. Profenofos is an Organophosphorous compound and acaricide used in Egypt with cumulative toxic effects causing reproductive dysfunction and increase in reactive oxygen species production. Protective and anti-oxidant effects of selenium can improve the activity of radical scavenger. So, the aim of this study was to elucidate the protective effects of Selenium against reproductive toxicity induced by Profenofos in male and female New Zealand rabbits (n=18). Three experimental groups (3 males and 3 females per each group) receiving a combination of Profenofos (70 mg/ kg b. w.) and/or selenium in drinking water (25 mg/ kg b. w.) for 90-day was divided as follows: non treated (control), Profenofos alone and Profenofos + selenium group. Profenofos caused a decrease in body and organs weights compared to control group. It had a fetotoxic effect resulting in a significant reduction in pregnancy rate and the number of viable feti in treated animals. Also, Profenofos caused a significant elevation in ALT, AST, MDA, urea and creatinine, while a significant decrease was noticed in SOD, GSH, testosterone, estrogen and progesterone in all treated rabbits compared to control group. Concomitant administration of selenium with Profenofos alleviated the induced alterations. In addition to, histopathological results revealed that testes, epididymis, ovary and uterus alterations represented by degenerative and inflammatory changes as a result of Profenofos exposure. Profenofos had a carcinogenic effect on uterus as leiomyoma with rhabdomyosarcoma which gave positive immunoreactivity with Desmin and Smooth muscle actin. Also, Profenofos caused histopathological and histochemical effects in liver and kidney tissues. There was intensive positive immunoreactivity for caspase- 3 (dark brown granules) was observed in the cytoplasm of apoptotic testicular, ovarian and uterine cells that indicating the severity of Profenofos toxicity. On the other hand, examined tissues of Profenofos in combination with selenium treated group showed apparent reduction of caspase-3 immunoreactivity to be more or less similar to the control group. In conclusion, selenium is a valuable cytoprotective which reduced the oxidative stress toxicity induced by Profenofos in the reproductive system of male and female as well as liver and kidney albino rabbits. Correspondence to: hanaa ali El-Hallawany hanaeg2002@yahoo.com 1. INTRODUCTION: Organophosphorous compounds (OPIs) are synthetic pesticides that developed in the last 50 years and are commonly used in agriculture (Salem and Kobeasy, 2006) .Due to their wide use, they contaminate food, water and air and consequently adverse health effects in humans, animals and fish (Sharma et al., 2005). The use of pesticides not only increases the crop yields but also helps in controlling ectoparasites on livestock. Residues of the grain protecting pesticides may also come in feeds and causes severe acute and chronic poisoning in farm animals and human as a result of its harmful commutative effect (Memon et al., 2014). Pesticides in the environment may play an important role in contributing the causes of fertility problems in dairy livestock as a result of endocrine imbalance (Campagna et al. 2009). The exposure of males to