title: Protection of negative gravitaxis in Euglena gracilis Z against gamma-ray irradiation by Trolox C.
abstract: The protective effects of Trolox on the inhibition of negative gravitaxis in Euglena gracilis exposed to 200 Gy 60Co gamma-rays were examined using different concentrations (1, 10 and 100 microM). The orientation precision of the negative gravitaxis was quantified using the r-value. A significant decrease in the r-value was observed in gamma-irradiated samples (0.18+/-0.03) compared to those of non-irradiated samples (0.47+/-0.03). There were no significant changes in the r-value of cells exposed to 200 Gy gamma-rays by the addition of 1 or 10 microM of Trolox. A significant increase (0.19) in the r-value of cells exposed to 200 Gy with 100 microM Trolox was observed. The results indicates that Trolox at a concentration of 100 microM protects negative gravitaxis against 60Co gamma-ray irradiation at a dose of 200 Gy. It also suggests that the negative gravitaxis of Euglena gracilis is affected by free radicals.
authors.affiliation: Research Center for Radiation Safety, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan. tetsuya@nirs.go.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sakashita
authors.forename: Masahiro
authors.initials: M
authors.lastname: Doi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yasuda
authors.forename: Shoichi
authors.initials: S
authors.lastname: Fuma
authors.forename: Donat-P
authors.initials: DP
authors.lastname: Häder
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D002839:Chromans / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005056:Euglena gracilis / Q000187:drug effects* / Q000528:radiation effects*; D005720:Gamma Rays / Q000009:adverse effects*; D018466:Gravity Sensing / Q000187:drug effects* / Q000528:radiation effects*
chemical_list: D000975:Antioxidants; D002839:Chromans; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid