The Effect of UV-B Radiation on Bufo arenarum Embryos Survival and Superoxide Dismutase Activity

J. HERKOVITS, J. L. D ERAMO AND O. FRIDMAN

International journal of Environmental research and public health

Wiley Interscience

Lugar: Basel, Siuza; Año: 2006 vol. 3 p. 43 - 47

1661-7827

ABSTRACT   The exposure of Bufo arenarum embryos to 302 nm UV-B  at a dose of  4,104 Joule/m2 resulted in 100% lethality within 24 hr while 820 Joule/m2 was the NOEC value for short-term chronic (10 days) exposure. The Toxicity Profile curves (TOPs) show that lethal effects increase with the dose and the time 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/m2 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 at 2 hr post exposure significantly higher values than in control embryos.