Nonylphenol provokes a vesiculation of the Golgi apparatus in three fish epidermis cultures

Exposure to nonylphenol impairs oocyte quality via the induction of organelle defects in mice

Nonylphenol (NP) is an environmental endocrine disruptor, which is mainly used in the production of surfactants, lubricants, additives, pesticides, and emulsifiers. NP is widely found in sewage and sludge, which has neurotoxicity, immunotoxicity, metabolic toxicity and reproductive toxicity. In this study, we investigated the effects of NP exposure on mammalian oocyte quality from organelle aspects with mouse in vivo model. The results showed that the ovarian weight of mice exposed to 500 μg/L NP for 4 weeks increased and the development ability of oocytes decreased, showing with lower rate of polar body extrusion. Further analysis indicated that exposure to NP caused the abnormal distribution of mitochondria, following with altered membrane potential drop. NP exposure disrupted the spindle periphery localization of ER, and affected the expression of GRP78 for the induction of ER stress. Moreover, Golgi apparatus fragment in the oocytes was observed, and Rab11-based vesicle transport was disturbed. We also found that the protein degradation might be affected since LAMP2 expression increased and LC3 decreased, indicating the lysosome and autophagy dysfunction. Taken together, our findings suggested that the exposure of NP to mice in vivo affected oocyte quality through its effects on the distribution and function of organelles.

Effects of alkylphenols on glycerophospholipids and cholesterol in liver and brain from female Atlantic cod (Gadus morhua)

Offshore oil production releases large amounts of lipophilic compounds in produced water into the ocean. In 2004, 143 million m(3) produced water, containing approximately 13 tons of long-chain (>C(4)) alkylphenols (AP), was discharged from installations in the Norwegian sector of the North Sea. Long-chain APs are known to cause endocrine disruption in a number of species. However, relatively little is known about their long-term effects in the marine environment. In the present study, Atlantic cod (Gadus morhua) were exposed (0.02 to 80 mg AP/kg) to a mixture (1:1:1:1) of APs (4-tert-butylphenol, 4-n-pentylphenol, 4-n-hexylphenol and 4-n-heptylphenol) or 17 beta-estradiol (5 mg E2/kg) for 5 weeks and the effect on the fatty acid profile and cholesterol content in the membrane lipids from the liver and the brain was studied. We also determined the interaction between different para-substituted APs and glycerophospholipids (native phospholipids extracted from cod liver and brain) and model phosphatidylcholine (PC 16:0/22:6 n-3) in monolayers with the Langmuir-Blodget technique. The study demonstrated that APs and E2 alter the fatty acid profile in the polar lipids (PL) from the liver to contain more saturated fatty acids (SFA) and less n-3 polyunsaturated fatty acids (n-3 PUFA) compared with control. In the brain of the exposed groups a similar effect was demonstrated, although with higher saturation of the fatty acids found in the neutral lipids (mainly cholesterol ester), but not in the polar lipids. The AP and E2 exposure also gave a decline in the cholesterol levels in the brain. The in vitro studies showed that APs increased the mean molecular areas of the PLs in the monolayers at concentrations down to 5 microM, most likely due to intercalation of the APs between PL molecules. The increase in molecular area increased with the length of the alkyl side chain.

A permanent fish cell line (EPC) for genotoxicity testing of marine sediments with the comet assay

Genotoxicity and cytotoxicity were evaluated in an in vitro system with a permanent cell line Epithelioma papulosum cyprini (EPC) derived from a skin tumour of carp (Cyprinus carpio L.). EPC cells were exposed to different concentrations of organic sediment extracts from the North Sea for 24h. After incubation the cells were analysed for viability and DNA strand breaks with the comet assay or single cell gel electrophoresis (SCGE). The results confirm the sensitivity of this assay. Out of 10 marine sediment samples from the North Sea, 9 showed a dose-dependent genotoxic effect. The EC(50) of sediment extracts ranged from 7 to 307 mg sediment dry weight/ml assay volume. Hepatic microsomal enzymes from dab (Limanda limanda L.) was proposed for enzymatic activation of benzo[a]pyrene (BAP) or sediment extracts, respectively. The suitability of this in vitro test system for assessing genotoxic and cytotoxic effects of marine sediment extracts on EPC cells could be demonstrated.