Mekkawy H.A.^*, Massoud A.A.^**, Hammouda E.M.^***, Hassan M.A.^*

^*The National Center for Social and Criminological Research, P.O. Zamalek, P.C. 11561, Cairo, Egypt
^**Fac. Sci., Tanta University, Cairo, Egypt
^***Fac. Sci., Al-Azhar University, Cairo, Egypt

Cyanophos (Cyanox), an organophosphorus insecticide was tested for its mutagenic and teratogenic effects on chicken system. Also, its effect on nucleic acids (including both DNA and RNA) and total proteins were followed up.
Following treatment of Leghorn chickens with single oral doses of the Cyanophos (equalling to 3.083 and 6.167 mg/kg/day given for 5, 10, 15 and 20 consecutive days).
Changes in mutagenic and teratogenic effects as an index for evaluation of possible toxic effects, were monitored by measuring chromosomal aberrations of bone marrow cells, DNA, RNA and total proteins concentrations in the liver and brain cells of chickens and teratogenic effects on the embryonic development of chick embryos.
Results of the study showed the following: chromosomal aberrations of bone marrow cells were centromeric attenuation, ring shaped, stickness and end to end associations. A significant decrease of liver and brain DNA, RNA and total proteins synthesis after the use of the present agent, indicating toxic effect. Cyanophos induced various teratogenic effects in developing embryos on the 14 and 16 the day of incubation. The total body weights and lengths of the embryos treated with two doses decreased. Cyanophos also induced skeletal malformations by the reduction in ossification of the bones of skull, neck, ribs, central disc and phalanges. The effects were proportional to insecticide concentration and incubation period. The LD₅₀ value of cyanophos for chicken was found to be 616.7 mg/kg body weight and the sublethal dose was found to be 590 mg/kg weight. Results indicated that two doses of cyanophos were found to be mutagenic and teratogenic. High doses of cyanophos were more toxic than lower dose of cyanophos.