title: Mechanisms of chromium hexavalent-induced apoptosis in rat testes.
abstract: Hexavalent chromium (CrVI)-containing compounds, present in industrial settings and in the environment, are known as carcinogens and mutagens. The present study is designed to test the hypothesis that oxidative stress mediates CrVI-induced apoptosis in testis. Male Wistar rats received an intraperitoneal injection of potassium dichromate at doses of 1 and 2 mg kg-1. Superoxide anion production was assessed by the determination of the reduction of cytochrome c and iodonitrotetrazolium, lipid peroxidation (LPO), metallothioneins (MTs), and catalase (CAT) activity. Apoptosis was evaluated by DNA fragmentation detected by agarose gel electrophoresis. Germinal cells apoptosis was detected by toluidine blue staining. The expression of Bax and Bcl-2 proteins (Pts) was also investigated. After 15 days of treatment, an increase of LPO and MT levels occurred, while CAT activity was decreased. Testicular tissues of treated rats showed pronounced degradation of the DNA into oligonucleotides as seen in the typical electrophoretic DNA ladder pattern. Intense apoptosis was observed in germinal cells of Cr-exposed rats. Bax Pt expression was induced in spermatogonia and spermatocytes cells of CrVI-treated rats. In contrast, Bcl-2 Pt was occasionally observed in germ cells of CrVI-exposed rats. These results clearly suggest that CrVI subacute treatment causes oxidative stress in rat testis leading to apoptosis.
authors.affiliation: 1 Laboratory of Integrated Physiology, Faculty of Sciences, Bizerte, Jarzouna, Tunisia.
authors.forename: Neila
authors.initials: N
authors.lastname: Marouani
authors.affiliation: 1 Laboratory of Integrated Physiology, Faculty of Sciences, Bizerte, Jarzouna, Tunisia.
authors.forename: Olfa
authors.initials: O
authors.lastname: Tebourbi
authors.affiliation: 1 Laboratory of Integrated Physiology, Faculty of Sciences, Bizerte, Jarzouna, Tunisia.
authors.forename: Dorsaf
authors.initials: D
authors.lastname: Hallègue
authors.affiliation: 2 Department of Anatomy and Pathological Cytology, Farhat Hached University Hospital, Sousse, Tunisia.
authors.forename: Moncef
authors.initials: M
authors.lastname: Mokni
authors.affiliation: 2 Department of Anatomy and Pathological Cytology, Farhat Hached University Hospital, Sousse, Tunisia.
authors.forename: Mohamed Tahar
authors.initials: MT
authors.lastname: Yacoubi
authors.affiliation: 1 Laboratory of Integrated Physiology, Faculty of Sciences, Bizerte, Jarzouna, Tunisia.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Sakly
authors.affiliation: 3 Department of Reproductive Biology and Cytogenetics, Picardy University Jules Verne, Amiens, France.
authors.forename: Moncef
authors.initials: M
authors.lastname: Benkhalifa
authors.affiliation: 1 Laboratory of Integrated Physiology, Faculty of Sciences, Bizerte, Jarzouna, Tunisia.
authors.forename: Khémais Ben
authors.initials: KB
authors.lastname: Rhouma
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002274:Carcinogens, Environmental / Q000633:toxicity*; D002375:Catalepsy / Q000378:metabolism; D002857:Chromium / Q000633:toxicity*; D053938:DNA Fragmentation / Q000187:drug effects; D004587:Electrophoresis, Agar Gel; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013481:Superoxides / Q000032:analysis; D013737:Testis / Q000737:chemistry / Q000187:drug effects*
chemical_list: D002274:Carcinogens, Environmental; D002857:Chromium; D013481:Superoxides; C074702:chromium hexavalent ion
keywords: DNA fragmentation rat; Hexavalent chromium; apoptosis; oxidative stress; testis