title: Some properties of the signals involved in unirradiated zebrafish embryos rescuing α-particle irradiated zebrafish embryos.
abstract: OBJECTIVE
  The in vivo radiation-induced bystander effect (RIBE) and radiation-induced rescue effect (RIRE) induced between embryos of the zebrafish (Danio rerio) by alpha-particle irradiation were studied through the number of apoptotic signals revealed at 24 h post fertilization (hpf) through vital dye acridine orange staining.
  
  
  METHODS
  RIBE and RIRE were verified through the significant increase and decrease in apoptotic signals in the partnered bystander and irradiated embryos, respectively.
  
  
  RESULTS
  The medium transfer experiment where irradiated zebrafish embryos were rescued through immersion in the medium previously conditioned by a larger number of irradiated zebrafish embryos showed (a) the involvement of a released stress signal in the induction of RIRE, and (b) RIBE and RIRE signals had the same function. With the help of 500 μM of the specific nitric oxide (NO) scavenger cPTIO (2-(4carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide), NO was confirmed as an essential signaling molecule for inducing both the RIBE and RIRE. On the other hand, the treatment with 20 μM of the carbon monoxide (CO) releasing chemical CORM-3 (tricarbonylchloro(glycinato)ruthenium (II)) suppressed the manifestations of RIBE but did not suppress RIRE.
  
  
  CONCLUSIONS
  In conclusion, unirradiated zebrafish embryos need NO but not NO-induced damages to rescue α-particle irradiated zebrafish embryos.
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong.
authors.forename: E Y
authors.initials: EY
authors.lastname: Kong
authors.forename: V W Y
authors.initials: VW
authors.lastname: Choi
authors.forename: S H
authors.initials: SH
authors.lastname: Cheng
authors.forename: K N
authors.initials: KN
authors.lastname: Yu
mesh_terms: D000512:Alpha Particles / Q000009:adverse effects*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D001565:Benzoates / Q000494:pharmacology; D024201:Bystander Effect / Q000187:drug effects / Q000528:radiation effects*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D007093:Imidazoles / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D009942:Organometallic Compounds / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000528:radiation effects*; D013312:Stress, Physiological / Q000187:drug effects / Q000528:radiation effects; D013997:Time Factors; D015027:Zebrafish / Q000196:embryology*
chemical_list: D001565:Benzoates; D007093:Imidazoles; D009942:Organometallic Compounds; C476530:tricarbonylchloro(glycinato)ruthenium(II); C079393:1,3-dihydroxy-4,4,5,5-tetramethyl-2-(4-carboxyphenyl)tetrahydroimidazole; D009569:Nitric Oxide
keywords: Bystander effect; alpha emitters; nitric oxide