eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2016-08-21 9 2 761 767 10.13005/bpj/1000 7398 article Fatemeh Nikpour 1 Jafar Soleimani Rad 2 Fatemeh Nikpour; Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. Jafar Soleimani Rad; Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. Drugs which are used in chemotherapy to cure cancer, generated destruction effects in sensitive of organs as testies. These substances are disrupted Spermatogenesis. the aim of this Study is investigating protective effects of cetrorelix from side effects of Vincristin 30 adult male mice were divided into 3 equal groups as: control, vincristine (V) and vincristine + cetrorelix (V+C) groups. A single dose of Vincristine was injected as ip at 1.5 mg/kg. In V+C group cetrorelix injection was started one week before vincristine treatment. Mice in groups were sacrificed 35 days after vincristine injection. Half of testicular specimens were fixed in 2% glutaraldehyde (EM studies), one another of theirs were fixed in boueins fixative (LM studies); Electron microscopic study showed that in control group sertoli cell cytoplasm lie was on BL and there is BTB between them. In (V) group study showed that there were large spaces between sertoli cells and between sertoli and BL. Blood- Testis Barrier were so irregular. In (V+C) group sertoli cells were similar to control group;According to the result it is concluded that GnRH antagonist administration before cancer treatment could partially prevent the side effect of anticancer drugs. https://biomedpharmajournal.org/vol9no2/effect-of-gnrh-on-vincristine-induced-spermatogenic-defects-on-sertoli-cell-and-defect-produced-on-the-blood-testis-barrier-btb-a-morphological-study/ Vincristine chemotherapy GnRH sertoli cells Electron microscopic Blood- Testis Barrier (BTB)