Abstracts / Toxicology Letters 221S (2013) S59–S256 S109

P08-33Influence of media and N:P ratios on growth,microcystin production and gene expression ofa Microcystis aeruginosa strain

Stella Bortoli 1,∗, Diogo de Oliveira Silva 2, Dietrich A. Volmer 1,Ernani Pinto 2

1 Universität des Saarlandes, Saarbrücken, Germany, 2 UniversidadeFederal de São Paulo, Campus Diadema, Diadema - São Paulo, Brazil

Cyanobacteria are prokaryotic and photosynthetic organisms,which have been found on all continents. They are of great concernbecause they have the ability to produce a variety of toxins, namelycyanotoxins. In this work we describe the influence of differentnutritional conditions (ASM-1 and BG-11 media at different N:Pratios: N:P = 10 and N:P = 100) on a Microcystis aeruginosa strain’s(LTPNA 02) growth (by cell counting), microcystin production (byLC–MS) and gene expression (mcyB) (by relative quantitation ��Ctand phycocyanin gene (cpc) as endogenous control). Statisticalanalysis was performed using ASM-1 N:P = 10 condition as control.The results highlight differences for growth, toxin production andgene expression. The growth in BG-11 N:P = 100 was higher thancontrol (p < 0.002) during the logarithmic phase. Experiments per-formed in BG-11 (N:P = 10 and 100) showed lower cell countingat the end of the experiment (p < 0.03 and p < 0.001). Three micro-cystin (MC) variants were quantified: MC-LR, MC-RR and MC-YR.The intracellular MC production reached the highest concentrationat the end of the experiment. The MC production was higher forexperiments using ASM-1 and BG-11 in N:P = 100 ratio (p < 0.05).The gene expression assay revealed enhancement at expression ofthe gene mcyB in BG-11 N:P = 10 ratio at days 5, 10 and 20 (p < 0.04).We concluded that nutritional condition, especially N:P ratio, havestrong influence on the growth and microcystin production, butthe exact effects at toxin biosynthesis, especially the gene mcyBexpression, is not entirely clear.

http://dx.doi.org/10.1016/j.toxlet.2013.05.172

P08-34Interaction between aluminum, nickel,thallium and uranium and essential elements(Ca, Mg, Zn, Se, Mn, Co, Cr and Mo) in humanblood and serum

Lulzim Zeneli 1, Jasna Jurasovic 2, Martina Piasek 2, Nexhat Daci 3

1 Institute of Biochemistry, Faculty of Medicine, University ofPrishtina, Kosovo, 2 Institute of Medical Research and OccupationalHealth, Zagreb, Croatia, 3 Department of Chemistry, University ofPrishtina, Kosovo

Purpose: Relationship between toxic and essential elements inhuman organism, at low levels of exposure are the capital for theadvancement of knowledge on the pathological mechanisms ofexposure to metals of the human population affected by heavymetal pollution. This study provide an overview of the influenceof exposure to aluminum, nickel, thallium and uranium on themetabolism of essential elements in the humans, as well as, therelationship between uranium, thallium, nickel, and aluminum andessential trace elements (Ca, Mg, Zn, Se, Mn, Co, Cr, and Mo) in thewhole blood and blood serum of healthy man industrial workers.

Methods: This study includes 97 human blood samples, 70 bloodsamples of the workers occupationally exposed (workers of ThermoPower Plant “Kosova”) and 27 blood samples from the control group

(inhabitants of the municipality of Dragash, pure locality, outsidethe influence of the pollution).

Results and conclusions: The results showed that chronic mod-erate exposure is associated with decreased serum chromium(SCr) and blood molybdenum (BMo) levels, whereas by the resultsachieved in terms of correlations between non-essential and essen-tial elements, non-essential elements as uranium, thallium, nickel,and aluminum despite their concentration within the reference val-ues are strongly competitive of essential elements in biochemicalprocesses.

http://dx.doi.org/10.1016/j.toxlet.2013.05.173

P08-35Lack of association between serum prolactinand lead exposure

Aysegul Bacaksiz 1, Meside Gunduzoz 2, Sedat Abusoglu 3, EnginTutkun 2, Hinc Yilmaz 2, Nilgun Giynas 2, Emine Gul Aydin 2

1 Kastamonu University, Fazıl Boyner School of Health, Department ofNutrition and Dietetics, Kastamonu, Turkey, 2 Department ofOccupational Toxicology, Ankara Occupational Diseases Hospital,Ankara, Turkey, 3 Selcuk University, Selcuk Faculty of Medicine,Department of Biochemistry, Konya, Turkey

Background: Serum prolactin (S-PRL) has been reported as abiomarker of early neurotoxic effect related to lead exposure.Raised S-PRL levels are generally considered to provide indi-rect evidence of reduced dopaminergic tuberoinfundibular (TIDA)activity. Elevated serum prolactin levels were reported due to lead-exposure. Our aim was to determine the change in serum prolactinlevels with lead-exposure.

Methods: Serum and whole blood samples were collected from72 non-exposed and 35 lead-exposed male workers. Blood leadwas analyzed by inductively coupled plasma – mass spectrometer.Serum prolactin levels were analyzed by immunological method.Serum alkaline phosphatase and whole blood count were analyzedby using commercial kits.

Results: Although serum prolactin levels were higher in lead-exposed group compared to control group (23.8 ± 71.3 vs 12.5 ± 7.2,respectively), this difference was not statistically significant(p = 0.552). While serum alkaline phosphatase (ALP) levels werehigher (203.5 ± 51.4 vs 136.3 ± 65.7, respectively) (p < 0.001), meancorpuscular hemoglobin concentration (MCHC) was lower in lead-exposed group compared to non-exposed group (33.2 ± 0.6 vs33.9 ± 1.4, respectively) (p = 0.001).

Conclusion: Serum prolactin level is not a diagnostic marker fordetermining the effect of lead-exposure.

http://dx.doi.org/10.1016/j.toxlet.2013.05.174

P08-36Mercury levels in placentas from non-exposedmothers

Tülin Söylemezoglu, Zeliha Kayaaltı, Seda Kaya, Vugar Ali Türksoy

Ankara University, Institute of Forensic Sciences, Turkey

Mercury is a xenobiotic metal that is a highly deleterious envi-ronmental pollutant, with recognized mutagenic and teratogeniceffects. Fetus is exposed to mercury via prenatal transfer acrossthe placenta, and after birth, they may be continue to be exposedto mercury through breastfeeding, by ingesting breast milk. The

S110 Abstracts / Toxicology Letters 221S (2013) S59–S256

toxicological effects of mercury vapors can be more devastatingto children compared to adults. Because, the nervous system anddetoxifying mechanisms of children is not developing yet, theblood–brain barrier of children is less able to keep mercury out ofbrain; the respiration rate of children is higher than that of adults.The aim of this study was to determine the mercury levels in pla-centa samples. For this purpose, placenta samples taken from113healthy mothers (mean ages 28.80 ± 5.12 years; ranging from 19 to41 years) were used. Mercury levels were quantified using graphiteatomic absorption spectrometry (GFAAS). The average mercurylevel within the placental tissues was found as 12.32 ± 11.25 ppb(Min: 3.08 ppb, Max: 87.58 ppb). Samples were subdivided into twogroups according to mothers’ ages as <35 (n = 98) and >35 (n = 15).When the mercury levels were compared with age groups, mer-cury levels in >35 years group were higher than <35 years group(16.78 ± 11.73 ppb versus 11.64 ± 11.02 ppb), but this result wasnot statistically significant (p > 0.05). On the other hand, numbersof mothers’ dental amalgam fillings and placental mercury levelswere considered, however, statistically significant association wasnot found.

http://dx.doi.org/10.1016/j.toxlet.2013.05.175

P08-37Mercury-resistant bacteria from Tagus Estuary– Characterization and mercury reductionpotential

Neusa L.L. Figueiredo 1, João Canário 2, Aida Duarte 1, CristinaCarvalho 1,∗

1 iMed.UL, Research Institute for Medicines and PharmaceuticalSciences, Faculty of Pharmacy, University of Lisbon, Av. Prof. GamaPinto, 1649-003 Lisbon, Portugal, 2 IPMA I.P., Division ofEnvironmental Oceanography and Bioprospection, Av. Brasília,1440-006 Lisbon, Portugal

In natural systems, mercury may be present in differ-ent chemical species, namely the mercuric form (Hg2+) andmonomethylmercury (MeHg). Mercury is toxic for all organisms,but after prolonged exposure some bacteria develop resistancemechanisms that confer mercury transformation capacity, such asHg2+ reduction. High level of Hg2+ and MeHg has been showed inTagus Estuary. In our study, we have been isolated and character-ized organic and inorganic mercury-resistant bacteria from highlymercury contaminated areas of Tagus Estuary. In this study, wedescribe the Hg2+ reduction of aerobic mercury-resistant bacteriaisolated in our study.

Mercury-resistant bacterial strains isolated from sedimentswere identified by 16S rRNA sequencing and their resistance tomercury compounds was evaluated by the determination of min-imal inhibitory concentration (MIC). PCR to detect the presence ofmer operon genes, which may be responsible for mercury reductioncapability, was performed. In parallel, mercury reduction capaci-ties were also evaluated. The results showed that these bacteriaare mercury resistant, being MIC values of Hg2+ and MeHg rangedfrom 0.1 to 13.6 �g/ml and 0.02 to 1.3 �g/ml, respectively, and thattheir resistance levels depend on their location. Although, only onebacterium showed a positive result for mer operonamplification,in presence of HgCl2, almost all bacteria showed ability to reduceit into Hg0, following volatilization process. The rate of reductionvaried amount bacterial strains tested, which may be as the resultof different mechanism of resistant. Thus, this work is the firstevidence of these bacteria role in mercury cycling in Tagus Estuary.

http://dx.doi.org/10.1016/j.toxlet.2013.05.176

P08-38Neurobehavioral effects of exposure toenvironmental chemicals and caesium indeveloping offspring mice

Isabel Llovet 1, Daisy Lafuente 1, Sergio Gonzalo 1, MontserratBellés 1,2, José Luís Domingo 1, Victòria Linares 1,2,∗

1 Laboratory of Toxicology and Environmental Health, School ofMedicine, IISPV, University Rovira I Virgili (URV), C/ Sant Llorenc 21,43201 Reus, Spain, 2 Physiology Unit, School of Medicine, IISPV,University Rovira I Virgili (URV), C/ Sant Llorenc 21, 43201 Reus,Spain

Epidemiological studies show that the exposure to low dosesof radiation during prenatal period of brain development causes ahigher incidence of neurological disorders and cognitive defects.Moreover, exposure to environmental chemicalssuchas bisphenol-A (BPA) and methylmercury (MeHg) may potentiate, particularlyon the brain, the toxic effects induced by ionising radiation onfetal development. The aim of this study was to investigate theimpact of BPA and MeHg in the effects of the radiation during brainfetal development. We used nine groups of pregnant C57BL/6J mice(n = 10 each group). From gestational day 16 through day 21 of lac-tation, two groups of animals were exposed to 137Cs through thedrinking water at activities of 4000 and 8000 Bq/kg. Environmentalchemicals, BPA and MeHg, were given orally during the same period(25 �g/kg/day and 20 �g/kg/day). Four other groups received 137Cscombined with BPA or MeHg at a doses described. Finally, onegroup did not receive any treatment and was considered the con-trol group. Behavioral tasks were tested in the offspring at 2 and 4months of age. The results showed that motor coordination on therotarod and behavior were not affected when radiation or chemi-cals were administered alone. However, alterations in spontaneousbehavior, anxiety, learning and memory capacities were detectedin groups exposed to radiation combined with BPA and MeHg.

http://dx.doi.org/10.1016/j.toxlet.2013.05.177

P08-39NOEC versus EC10, reloaded on a recent showcase

Eunsoo Jung 1,∗, Ralf Arno Wess 2, Thomas Schmidt 2

1 LG Life Sciences, Korea, 2 Harlan Laboratories, Itingen, Switzerland

The DPP-4 inhibitors Gemigliptin, Linagliptin, Saxagliptin,Sitagliptin and Vildagliptin were evaluated for possible environ-mental impact according to the standards of EM(E)A guidance(2006, 2011) for Environmental Risk Assessment. The lowest NOECto aquatic organisms of the first three trophic levels serves as PointOf Departure (POD) to derive the Predicted No Effect Concentra-tion (PNEC) in the environment. The Risk Characterisation Ratio(RCR) is then calculated using the Predicted Environmental Con-centration (PEC) by PNEC/PEC = RCR. It may be assumed that a RCRcomparison could be used to rank similar compounds with regardto environmental impact.

In the case of Gemigliptin the algal NOEC and EC10 arevery different due to the flat dose–effect ratio: NOEC = 230�g/L,EC10 > 100 mg/L. Thus the use of NOEC would result in raising the“T” flag “very toxic”, while EC10 clearly demonstrates that algaleffects are out of relevance for aquatic toxicity assessment (in linewith CLP-classification) and “practically non-toxic”.

Therefore, the use of NOEC as the right measure to assess on tox-icity, may be questioned. Interestingly the EM(E)A guidance does