title: On the mechanism of biological activation by tritium.
abstract: The mechanism of biological activation by beta-emitting radionuclide tritium was studied. Luminous marine bacteria were used as a bioassay to monitor the biological effect of tritium with luminescence intensity as the physiological parameter tested. Two different types of tritium sources were used: HTO molecules distributed regularly in the surrounding aqueous medium, and a solid source with tritium atoms fixed on its surface (tritium-labeled films, 0.11, 0.28, 0.91, and 2.36 MBq/cm(2)). When using the tritium-labeled films, tritium penetration into the cells was prevented. The both types of tritium sources revealed similar changes in the bacterial luminescence kinetics: a delay period followed by bioluminescence activation. No monotonic dependences of bioluminescence activation efficiency on specific radioactivities of the films were found. A 15-day exposure to tritiated water (100 MBq/L) did not reveal mutations in bacterial DNA. The results obtained give preference to a "non-genomic" mechanism of bioluminescence activation by tritium. An activation of the intracellular bioluminescence process develops without penetration of tritium atoms into the cells and can be caused by intensification of trans-membrane cellular processes stimulated by ionization and radiolysis of aqueous media.
authors.affiliation: Krasnoyarsk State Medical Academy, P.Zheleznyaka 1, Krasnoyarsk, 660022, Russia; Siberian Federal University, Svobodny 79, Krasnoyarsk, 660041, Russia.
authors.forename: T V
authors.initials: TV
authors.lastname: Rozhko
authors.affiliation: Moscow State University, Department of Chemistry, Moscow, 119991, Russia.
authors.forename: G A
authors.initials: GA
authors.lastname: Badun
authors.affiliation: Moscow State University, Department of Chemistry, Moscow, 119991, Russia.
authors.forename: I A
authors.initials: IA
authors.lastname: Razzhivina
authors.affiliation: Siberian Federal University, Svobodny 79, Krasnoyarsk, 660041, Russia.
authors.forename: O A
authors.initials: OA
authors.lastname: Guseynov
authors.affiliation: Siberian Federal University, Svobodny 79, Krasnoyarsk, 660041, Russia.
authors.forename: V E
authors.initials: VE
authors.lastname: Guseynova
authors.affiliation: Siberian Federal University, Svobodny 79, Krasnoyarsk, 660041, Russia; Institute of Biophysics SB RAS, Akademgorodok 50/50, Krasnoyarsk, 660036, Russia. Electronic address: n_qdr@yahoo.com.
authors.forename: N S
authors.initials: NS
authors.lastname: Kudryasheva
mesh_terms: D004269:DNA, Bacterial / Q000528:radiation effects; D049449:Luminescence; D010776:Photobacterium / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D014316:Tritium / Q000494:pharmacology*; D014875:Water Pollutants, Radioactive / Q000494:pharmacology*
chemical_list: D004269:DNA, Bacterial; D014875:Water Pollutants, Radioactive; D014316:Tritium
keywords: DNA mutations; Low-dose effect; Luminous marine bacteria; Radiation hormesis; Tritium