S190 Abstracts / Toxicology Letters 211S (2012) S43–S216 P31-03 Investigation of potential mechanisms and biomarkers for kidney toxicity in the rat Anita Annas 1 , Kerstin Kenne 2 , Anders Samuelsson 2 , Susanne Bran 2 , Christine Lindqvist 2 , Christina Björklund 2 , Rolf Johansson 3 1 AstraZeneca R&D, United Kingdom, 2 Safety Assessment, AstraZeneca R&D, United Kingdom, 3 iMed CNSP, AstraZeneca R&D, Sweden The present test compound has in previous toxicity studies been shown to induce kidney damage, including crystal formation in tubuli, in rats. The aim of this study was to explore mechanisms and potential biomarkers for assessing early lesions in the kidney. Groups of rats were given three different doses of the test com- pound for five days. The effects on the kidneys were evaluated by histopathology and measurements of kidney biomarkers in plasma and urine. Tubular dilatation and basophilia were observed in the kidney, and crystals were formed dose dependently. The damaged areas, which included both proximal and distal tubules, were found in triangular areas (probably damage to individual nephrons) sur- rounded by normal tissue. Minimal changes in classical kidney markers in plasma and urine were not conclusive. The urinary integrity markers, NAG, ALP, LDH, GGT, did not predict, nor con- firm, tubular histopathological alterations. Protein analysis of urine using 2-D gels showed that uromodulin was significantly decreased in the high dose group compared to control animals. In addition, urinary albumin was markedly increased in the animals with the most severe kidney histopathology. The kidney function was apparently not affected, possibly due to the reserve capacity of the kidneys. Since no, or only lim- ited, effects were seen on the urinary parameters, it is reasonable to assume that only urine from healthy nephrons was analysed and tubular-specific proteins, which would indicate cellular injury, were trapped by the crystals in the dilated tubules. No predictive biomarkers for this type of kidney damage were identified. doi:10.1016/j.toxlet.2012.03.683 P31-04 Investigation of different organophosphates in a human bronchial tripleculture model Marina Schäfer 1 , C. Pohl 1 , M. Moisch 1 , D. Steinritz 2 , K. Kehe 2 , C.J. Kirkpatrick 1 1 Johannes Gutenberg University Mainz, Germany, 2 Bundeswehr Institute of Pharmacology and, Germany Purpose: In vitro models are necessary to study pathome- chanisms of pulmonary toxicity. Lung-toxic substances such as organophosphates which are dangerous nerve agents are usually absorbed through inhalation. Methods: We used a primary human bronchial triple-culture model, which consists out of primary human epithelial cells from small bronchi (HBEC), lung fibrob- lasts and dendritic cells (DCs). The HBEC and the fibroblasts are cultured on a transwell filter membranes under air–liquid condi- tions for 28 days. DCs were differentiated from monocytes (cell line THP-1) with various cytokines (IL-4, GM-CSF, TNF-, iono- mycin) for 7 days and then added to the established DCs in the coculture model. Several organophosphates (e.g. dimethoate and chlorpyrifos) were tested at the triple-culture model of the secre- tion of proinflammatory mediators (e.g. IL-6, IL-8) and changes of cell–cell contacts by immunfluorescence. Results and conclusion: Organophosphates affected the triple culture depending on the concentration. At higher concentrations the cell–cell contacts in the coculture without DCs were destroyed whereas in triple cultures the DCs seem to compensate effects of the organophosphates. In our experiments DCs play an important role in the initial immune response against pulmonary toxins and carcinogens in lung. doi:10.1016/j.toxlet.2012.03.684 P31-05 Gingival hyperplasia in beagle dog treated with Cyclosporine A Paolo Angelo Colombo, Elena Riccardi, Guido Di Gallo, Francesco Marchesi, Anna Maria Giusti ACCELERA SRL, Italy In the context of a study aimed to investigate the potential toxicity of stem cells after repeated intra-arterial administration, escalating doses of stem cells were administered to a total num- ber of six male Beagle dogs for four times, three weeks apart, over a period of 64 days. Concurrently, treatment with Cyclosporine A (CYA) for preventing stem cells rejection was given to all treated dogs and to four control animals, with dose adjustments based on plasma levels and clinical tolerability. A 26-weeks observation period was applied after the last administration of stem cells. Clin- ical findings were noted in the skin and oral cavity in four animals, one control and three treated with stem cells. Cutaneous changes, consisting of epidermal thickening, were evident after 13 weeks of treatment, and regressed after the reduction of CYA dose. Gingi- val hyperplasia, starting from week 14, became progressively more severe persisting till the end of the observation period. At his- tological examination, marked acanthosis of mucosal epithelium associated with infiltration of inflammatory cells in the corion was observed. Gingival overgrowth has been reported to occur during CYA-based immunosuppressive therapy, to be directly related to CYA blood concentration and to be reversible after the discontinu- ation of drug administration. Similar findings during CYA treatment have been reported also in humans and rats. In conclusion, gingival overgrowth must be considered as a possible adverse effect during the administration of CYA as therapeutic or immunosuppressant agent, both in the clinical practice and during toxicological studies. doi:10.1016/j.toxlet.2012.03.685 P31-06 Histopathological findings, telomerase activity and ultrasound measurements in heart tissues after long-term rabbits exposure to turinabol and methanabol Christina Tsitsimpikou 1 , Konstantinos Tsarouchas 2 , Ioannis Germanakis 3 , Persefoni Fragkiadaki 2 , Maria Tzardi 2 , Demetrios Kouretas 4 , Ioannis Kalogerakis 2 , Konstantinos Lasithiotakis 3 , Aristidis Tsatsakis 2 1 General Chemical State Laboratory, Greece, 2 University of Crete, Greece, 3 General University Hospital of Heraklion, Greece, 4 University of Thessaly, Greece Purpose: Several cardiovascular complications including hyper- tension, cardiomegaly, and acute myocardial infarction are associated with the use of anabolic steroids. Turinabol (4 chloro- methandienone) and methanabol (methandienone) constitute two