Lethal and estrogenic effects of 4-nonylphenol in the cockle Cerastoderma glaucum.
March 16th, 2008 | by admin |Lethal and estrogenic effects of 4-nonylphenol in the cockle Cerastoderma glaucum.
The lethal and sublethal effects of the xenoestrogen 4-nonylphenol (NP) were evaluated in the cockle Cerastoderma glaucum. In a 96-h lethality test, bivalves were exposed to 0, 0+ acetone, 0.19, 0.38, 0.75, 1.5 and 3.0mg NP/l. The 96-h LC(50) value was 0.3mg NP/l. No mortality was observed at 0.1mg NP/l. The potential estrogenicity of NP was studied in both sexually undifferentiated (resting phase) and differentiated (pre-spawning phase) cockles, exposed for 7 and 14days to 0, 0+ acetone, 0.0125, 0.025, 0.05, and 0.1mg NP/l. Vitellogenin (Vg)-like protein levels were determined in both haemolymph and digestive gland by the alkali-labile phosphate (ALP) assay. In the resting phase, exposure for 7days to 0.1mg NP/l resulted in significant increases in ALP in both haemolymph and digestive gland, compared with controls. A significant increase was also observed in digestive gland of animals exposed to 0.0125mg NP/l-exposed animals. After 14days of exposure, haemolymph ALP levels were significantly increased in exposed animals at all NP concentrations tested, whereas no difference was recorded in digestive gland. In the pre-spawning phase, exposure for 7days to NP significantly increased ALP levels in haemolymph from males exposed at all NP concentrations tested, whereas no significant variations were found in haemolymph from females. NP (0.05 and 0.1mg/l) was also shown to increase ALP concentrations significantly in digestive gland of males, but not in those of females. Likewise, after 14 days\’ exposure, ALP levels significantly increased in haemolymph from males only at 0.1mg NP/l. Conversely, NP caused significant increases in ALP levels in digestive gland from both males (at all NP concentrations tested) and females (at 0.025 and 0.1mg NP/l). These results demonstrate that NP induces Vg synthesis in C. glaucum. Interestingly, males were more responsive to NP than females.
Marin MG, Rigato S, Ricciardi F, Matozzo V.
Department of Biology, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy.