title: Melatonin protects rat thymus against oxidative stress caused by exposure to microwaves and modulates proliferation/apoptosis of thymocytes.
abstract: The aim of the study was to evaluate the effect of melatonin on oxidative stress, DNA fragmentation, apoptsis and proliferation in thymus tissue of rats exposed to microwaves. Wistar rats were divided in four groups: I - treated with saline; II - treated with melatonin; III - microwaves exposed; IV - microwaves exposed and melatonin treated. Melatonin (2 mg/kg i.p.) was administered daily. Animals were sacrificed after 20, 40 and 60 days. A significant increase in malondialdehyde and carbonyl group content, as well as decrease in catalase and increase in xanthine oxidase activity were registered under microwave exposure. Melatonin prevented the increase in malondialdehyde and carbonyl group content, and reversed the effect on catalase and xanthine oxidase activity. Both, alkaline and acid DNase activity were increased due to microwave exposure. Furthermore, microwaves caused increase in apoptosis rate (detected using Annexin V-FITC/PI kit) and reduced proliferative capacity of thymocytes (induced by ConA). However, melatonin caused decrease in alkaline and acid DNase activity, decrease in apoptotic rate and increase in proliferation rate of thymocytes. Melatonin exerts protective effects on rat thymocytes by modulating processes of apoptosis and proliferation, and causes decrease in DNA fragmentation and oxidative stress intensity under exposure to microwaves.
authors.affiliation: Department of Biochemistry, University of Nis, Nis, Serbia. soko@medfak.ni.ac.rs
authors.forename: Dusan
authors.initials: D
authors.lastname: Sokolovic
authors.forename: Branka
authors.initials: B
authors.lastname: Djordjevic
authors.forename: Gordana
authors.initials: G
authors.lastname: Kocic
authors.forename: Andrej
authors.initials: A
authors.lastname: Veljkovic
authors.forename: Milena
authors.initials: M
authors.lastname: Marinkovic
authors.forename: Jelena
authors.initials: J
authors.lastname: Basic
authors.forename: Tatjana
authors.initials: T
authors.lastname: Jevtovic-Stoimenov
authors.forename: Zoran
authors.initials: Z
authors.lastname: Stanojkovic
authors.forename: Danka M
authors.initials: DM
authors.lastname: Sokolovic
authors.forename: Voja
authors.initials: V
authors.lastname: Pavlovic
authors.forename: Boris
authors.initials: B
authors.lastname: Djindjic
authors.forename: Dejan
authors.initials: D
authors.lastname: Krstic
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis; D002374:Catalase / Q000378:metabolism; D049109:Cell Proliferation; D053938:DNA Fragmentation; D003851:Deoxyribonucleases / Q000378:metabolism; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D008872:Microwaves; D018384:Oxidative Stress; D051381:Rats; D017208:Rats, Wistar; D060168:Thymocytes / Q000166:cytology*; D013950:Thymus Gland / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D013997:Time Factors; D014969:Xanthine Oxidase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002374:Catalase; D014969:Xanthine Oxidase; D003851:Deoxyribonucleases; D008550:Melatonin