Outcome of Angiotensin II Inhibition in Pregnant Irradiated Rats and their Embryos

The study aims to evaluate the synergism of losartan and or irradiation stress on the female rat mothers and their developing embryos as judged by the maternal biochemical pathways during gestation and teratogenic effects on the embryos. Losartan is an angiotensin II AT1-receptor antagonist used to regulate blood pressure. Losartan (5 mg/kg b.wt day) was daily orally administrated to pregnant rats from the 6 th to 18 th gestational days during which they were subjected to intermittent radiation dose levels of 0.5 Gy/4 times at the 9 th, 10 th, 11 th and 12 th days of gestation whereas investigation has been carried out one day prior to parturition. Dual treatment of losartan and radiation resulted in increased maternal serum levels of creatinine and bilirubin.The developing embryos in the uteri due to their high sensitivity showed various teratological, skeletal and histological impairment. Losartan and/or radiation induced effects were detected as growth retardation, malformations expressed as anopthalmia, kypophysis, subcutaneous haemorrhage and microtia as well as elevated intrauterium death and embryonic resorption. Moreover, the examination of endo skeletal system of fetuses showed retardation in the ossification of the skull bones and lack of ossification at the vertebrae and edges. Also, maternal and embryonic histological examination revealed that losartan and gamma radiation induced injury to kidney tissue manifested in rupture and shrinkage of renal corpuscle, infiltration, disappearance of glomularies, while the kidney of fetuses showed loss of renal pattern. Results point out that losartan should be used with caution in women at the reproductive age and those occupationally exposed to irradiation