Herkovits J, D'Eramo J L, Fridman O
Programa de Seguridad Química, Instituto de Ciencias Ambientales y Salud, Fundación PROSAMA, Paysandú, Buenos Aires,
Int J Environ Res Public Health. 2006 Mar;3(1):43-7. doi: 10.3390/ijerph2006030006.
The exposure of Bufo arenarum embryos to 300-310 nm UV-B at a dose of 4,104 Joule/m(2) resulted in 100% lethality within 24 hr while 820 Joule/m(2) was the NOEC value for short-term chronic (10 days) exposure. The dose response curves show that lethal effects are proportional with the dose and achieve its highest value within 48 hr post exposure. The superoxide dismutase (SOD) activity in amphibian embryos for sublethal UV-B exposures was evaluated by means of UV-B treatments with 273 (A), 820(B), 1368(C) and 1915(D) Joule/m(2) at 2 and 5 hours post irradiation. The SOD activity in units/mg protein in A, B, C and D at 2 hr after treatments were 80.72 +/- 14.29, 74.5 +/- 13.19, 39.5 +/- 6.99 and 10.7 +/- 1.89 respectively while for control embryos it was 10.88 +/- 1.31. At 5 hr after treatments the SOD values were similar to those found in control embryos. The results confirm the high susceptibility of amphibian embryos to UV-B and point out that the SOD activity is enhanced by low doses of UV-B irradiation achieving significantly higher values than in control embryos at 2 hr post exposure.
将南美蟾蜍胚胎暴露于剂量为4,104焦耳/平方米的300 - 310纳米UV - B下，24小时内死亡率达100%，而820焦耳/平方米是短期慢性（10天）暴露的无可见效应浓度值。剂量反应曲线表明，致死效应与剂量成正比，并在暴露后48小时内达到最高值。通过在照射后2小时和5小时用273（A）、820（B）、1368（C）和1915（D）焦耳/平方米的UV - B处理，评估两栖动物胚胎亚致死UV - B暴露下的超氧化物歧化酶（SOD）活性。处理后2小时，A、B、C和D组每毫克蛋白质中SOD活性的单位数分别为80.72±14.29、74.5±13.19、39.5±6.99和10.7±1.89，而对照胚胎为10.88±1.31。处理后5小时，SOD值与对照胚胎相似。结果证实两栖动物胚胎对UV - B高度敏感，并指出低剂量UV - B照射可增强SOD活性，在暴露后2小时达到显著高于对照胚胎的值。
