[Effects of low-dose tritiated water on the developing central nerve system and their mechanisms].
OBJECTIVE
To provide experimental data for evaluating tritium risk of nuclear-energy plant and instituting safety protection standard of nuclear effects of low-dose tritiated water(HTO) on the developing central nerve system.


METHODS
Pregnant adult C57BL/6J strain mice and Wistar rats were irradiated with beta-rays from HTO by a single intraperitoneal injection on the 12.5th and 13th day of gestation. The activity of HTO was (x 10(4) Bq/g. B.W) 24.09, 48.18 and 144.54, respectively. Neurobehavior and learning and memory ability were tested. Ca2+ currents of hippocampal neurons were examined by patch-clamp. Apoptosis of brain cells was detected morphologically and biochemically by DNA electrophoresis. SDS-PAGE and Western blotting were used to detect P53 protein in the cultures.


RESULTS
After irradiation with beta-rays from HTO in utero, the offspring showed hyperactivity in their young age period and then showed depression-hypoactivity in adulthood. The exposed animals had difficulties in both learning and memory retention and the developing neurons of the central nerve system showed lower Ca2+ currents, higher number of apoptosis, a typical "ladder pattern" DNA and increasing P53 protein.


CONCLUSIONS
Lower Ca2+ currents, higher number of apoptosis of brain cells and abnormal expression of P53 protein were the substance basis of the damage of central nerve system caused by tritium.
Zhou
X
X
Department of Toxicology, Laboratory of Industrial Hygiene, Ministry of Health, Beijing 100088, China.
Gao
W
W
Wang
B
B
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000528:radiation effects; D001522:Behavior, Animal / Q000528:radiation effects*; D001921:Brain / Q000378:metabolism / Q000528:radiation effects*; D005260:Female; D006624:Hippocampus / Q000473:pathology; D007858:Learning / Q000528:radiation effects; D008297:Male; D008568:Memory / Q000528:radiation effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D011247:Pregnancy; D011829:Radiation Dosage; D051381:Rats; D017208:Rats, Wistar; D014316:Tritium / Q000633:toxicity*
D014316:Tritium