Induction of cytogenetic adaptive response in spermatogonia and spermatocytes by pre-exposure of mouse testis to low-dose (12)C(6+) ions.
To investigate the effects of pre-exposure of mouse testis to low-dose (12)C(6+) ions on cytogenetics of spermatogonia and spermatocytes induced by subsequent high-dose irradiation, the testes of outbred Kun-Ming strain mice were irradiated with 0.05Gy of (12)C(6+) ions as the pre-exposure dose, and then irradiated with 2Gy as challenging dose at 4h after per-exposure. Poly(ADP-ribose) polymerase (PARPs) activity and PARP-1 protein expression were respectively measured by using the enzymatic and Western blot assays at 4h after irradiation; chromosomal aberrations in spermatogonia and spermatocytes were analyzed by the air-drying method at 8h after irradiation. The results showed that there was a significant increase in the frequency of chromosomal aberrations and significant reductions of PARP activity and PARP-1 expression level in the mouse testes irradiated with 2Gy of (12)C(6+) ions. However, pre-exposure of mouse testes to a low dose of (12)C(6+) ions significantly increased PARPs activity and PARP-1 expression and alleviated the harmful effects induced by a subsequent high-dose irradiation. PARP activity inhibitor 3-aminobenzamide (3-AB) treatment blocked the effects of PARP-1 on cytogenetic adaptive response induced by low-dose (12)C(6+) ion irradiation. The data suggest that pre-exposure of testes to a low dose of heavy ions can induce cytogenetic adaptive response to subsequent high-dose irradiation. The increase of PARP-1 protein induced by the low-dose ionizing irradiation may be involved in the mechanism of these observations.
Zhang
Hong
H
Department of Medical Physics, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China. zhangh@impcas.ac.cn
Zhao
Weiping
W
Wang
Yanling
Y
Li
Ning
N
Wu
Zhenhua
Z
Liu
Yang
Y
Chen
Jidong
J
Cai
Yujia
Y
D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D002244:Carbon; D002869:Chromosome Aberrations / Q000528:radiation effects; D033481:Chromosomes, Mammalian / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000528:radiation effects*; D020450:Heavy Ions; D008297:Male; D051379:Mice; D000071137:Poly (ADP-Ribose) Polymerase-1; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000096:biosynthesis*; D011836:Radiation Tolerance / Q000187:drug effects / Q000528:radiation effects*; D011839:Radiation, Ionizing; D013090:Spermatocytes / Q000201:enzymology* / Q000473:pathology; D013093:Spermatogonia / Q000201:enzymology* / Q000473:pathology
D001549:Benzamides; D004791:Enzyme Inhibitors; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D002244:Carbon; C025160:3-aminobenzamide; C499321:Parp1 protein, mouse; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases