Evaluation of renal toxicity of melamine, cyanuric acid and their mixture in F344 neonatal rats
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Abstracts / Toxicology Letters 205S (2011) S180–S300 S277 enzymes arachidonate 15-lipoxygenase type I (ALOX15B) and fatty acid binding protein 7 (FABP7) was 10-fold lower than that from vehicle-treated animals. No hamartomatous neoformations simi- lar to those seen in humans following acute TCDD exposure were observed in these mice following TCDD up to 10 weeks. In sum- mary topical TCDD induced a focal expression of CYP1A1 in mouse sebaceous glands, as well as sebaceous gland atrophy, but did not promote the development of the hamartomatous neoformations that characterise the chloracne syndrome in humans. These data indicate that sebaceous glands are a primary target of AhR ligands including TCDD in the skin. doi:10.1016/j.toxlet.2011.05.938 P2315 Valproate-induced liver mitochondrial dysfunction in rats: A metabonomic approach V. Tagliatti ∗ , R. Conotte, D. De Luca, J. Colet Human Biology and Toxicology, University of Mons – UMONS, Mons, Belgium Purpose: Due to its major role in drug metabolism, the liver is a first-line target organ of toxicity. Mitochondrial impairment is often a key player in hepatotoxicity but robust biomarkers of such subcellular effects are lacking for preclinical evaluation. Metabo- nomics studies based on spectroscopic analysis of biofluids has been recently shown as a valuable tool to identify drug-induced toxicity in vivo. In the present study, we evaluated the ability of MBX to detect mitochondrial impairment in an animal model of hepatotoxicity induced by valproate, an antiepileptic drug that has recently regain interest as anti-cancer drug. Methods: Three groups of male rats (n = 5/group) received either saline or valproate once a day during 2 or 4 days (750 mg/kg, s.c.). Liver injury was con- firmed by conventional biochemical assays and histopathology. Urine and plasma samples, collected before and after dosing, as well as methanol/chloroform/water liver extracts and bile samples were analyzed by 1 H NMR spectroscopy. Results: Valproate caused significant decreases in urine levels of many endogenous metabo- lites. Most important changes, associated with liver injury, included decreases in hippurate and taurine. More specific changes could be linked to mitochondria impairment, i.e. decreases in citrate, succinate and a-ketoglutarate levels. Methanol/chloroform/water liver extracts showed a large range of modifications correlated with histological results. In conclusion, this study indicates that urinary toxicometabonomics could be used to assess target organ drug toxi- city non-invasively on animal models and identify early biomarkers of liver damage. Moreover, MBX could be also used to evaluate subcellular toxicity like mitochondrial disruptions. doi:10.1016/j.toxlet.2011.05.939 P2316 Evaluation of renal toxicity of melamine, cyanuric acid and their mixture in F344 neonatal rats G. Woo Toxicology & Chemistry Division, National Veterinary Research and Quarantine Service, Anyang-si, Republic of Korea Purpose: Both of melamine (2,4,6-triamino-1,3,5-triazine, MEL) and cyanuric acid (CYA) can be found in food because of wide use and existence in mixed forms in environment. This study was conducted to compare the potency of renal toxicity among MEL, CYA and Mel + Cya using novel biomarkers for the renal toxicity in neonatal rats. Methods: One-day-old male and female neonatal rats (Fischer 344/N Slc) were administered with 1% carboxylmethyl- cellulose (CMC, 5 ml/kg bw, vehicle control), MEL (10, 35 and 118 mg/kg bw), CYA (150 mg/kg bw), MEL + CYA (0.35, 1, 3.5 mg/kg bw, respectively) via gavage once per day for 4 wks. Blood was collected from abdominal artery in the next day of the last admin- istration. Urine samples were collected through metabolic cage and stored at −80 ◦ C. The concentrations of KIM-1, TIMP-1, VGEF, clus- terin, NGAL and osteopontin for renal cell damage and 2m, GST-, Calbindin and Cystantin-C for renal function disorders in serum and urine were analyzed using a bio-plex system. Results: TIMP-1 and clusterin in urine were significantly increased by CYA alone and MEL + CYA treatment. TIMP-1 in serum were decreased in male and female rats by MEL + CYA (3.5 mg/kg bw). Cystatin-C in serum was increased in female rats by 3.5 MEL + CYA. Osteopontin in serum was decreased in male rats by 3.5 MEL + CYA. Urinary TIMP-1 and clusterin were increased in female rats by CYA and 3.5 MEL + CYA, respectively. Serum TIMP-1, serum osteopontin urinary TIMP-1 and urinary clusterin could be used as sensitive biomarker for the renal toxicity of MEL+CYA. doi:10.1016/j.toxlet.2011.05.940 P2317 Differential effects of methylazoxymethanol and MK-801 administration on learning and memory impairment in Sprague Dawley and Wistar Han rats A. Zmarowski ∗ , M. Beekhuijzen, M. Teunissen, H. Emmen Toxicology, NOTOX B.V., ‘s-Hertogenbosch, The Netherlands Wistar Han (WH) and Sprague Dawley (SD) rats are the pre- ferred strains for Europe and the US, respectively, though both are acceptable for EU and US test guidelines. Potential differences in behavioral performance between the strains have not been exten- sively investigated, though unexpected differences between strains could complicate risk assessment. Learning and memory testing was conducted within a developmental neurotoxicity study. Three groups were used for each strain. F0-females received saline or 20 mg/kg methylazoxymethanol (MAM; known to produce neuro- pathic and behavioral alterations in offspring) intra-peritoneally on gestation Day15. Animals littered, and offspring were tested in the Biel maze at weaning (PNDs 22–28) or adulthood (PNDs 62–68). On days of testing, animals were given saline or 0.1 mg/kg MK-801, which impairs learning and memory performance. Animals swam ‘path A,’ were then switched to an alternative ‘path B,’ and were last switched back to ‘path A’ for the memory test. Time to escape the maze and number of errors were quantified. Both strains learned each path, both remembered ‘path A’ when tested, and both were impaired with MK-801 administration. However, strain differences were evident: in general, SD rats learned better than WHs (taking less time and making fewer errors). They were also more impaired with MAM treatment, with more time and errors than WHs. Con- versely, WH rats were more impaired with MK-801 administration, especially over ‘path B’. In conclusion, these data highlight differ- ences in general test performance and in drug sensitivity between the strains, which could ultimately require consideration in risk assessment. doi:10.1016/j.toxlet.2011.05.941
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Abstracts / Toxicology Le
nzymes arachidonate 15-lipoxygenase type I (ALOX15B) and fattycid binding protein 7 (FABP7) was 10-fold lower than that fromehicle-treated animals. No hamartomatous neoformations simi-ar to those seen in humans following acute TCDD exposure werebserved in these mice following TCDD up to 10 weeks. In sum-ary topical TCDD induced a focal expression of CYP1A1 in mouse
ebaceous glands, as well as sebaceous gland atrophy, but did notromote the development of the hamartomatous neoformationshat characterise the chloracne syndrome in humans. These datandicate that sebaceous glands are a primary target of AhR ligandsncluding TCDD in the skin.
oi:10.1016/j.toxlet.2011.05.938
2315alproate-induced liver mitochondrial dysfunction in rats: Aetabonomic approach
. Tagliatti ∗, R. Conotte, D. De Luca, J. Colet
Human Biology and Toxicology, University of Mons – UMONS, Mons,elgium
Purpose: Due to its major role in drug metabolism, the liver isfirst-line target organ of toxicity. Mitochondrial impairment is
ften a key player in hepatotoxicity but robust biomarkers of suchubcellular effects are lacking for preclinical evaluation. Metabo-omics studies based on spectroscopic analysis of biofluids haseen recently shown as a valuable tool to identify drug-inducedoxicity in vivo. In the present study, we evaluated the ability of
BX to detect mitochondrial impairment in an animal model ofepatotoxicity induced by valproate, an antiepileptic drug that hasecently regain interest as anti-cancer drug. Methods: Three groupsf male rats (n = 5/group) received either saline or valproate onceday during 2 or 4 days (750 mg/kg, s.c.). Liver injury was con-
rmed by conventional biochemical assays and histopathology.rine and plasma samples, collected before and after dosing, asell as methanol/chloroform/water liver extracts and bile samplesere analyzed by 1H NMR spectroscopy. Results: Valproate caused
ignificant decreases in urine levels of many endogenous metabo-ites. Most important changes, associated with liver injury, includedecreases in hippurate and taurine. More specific changes coulde linked to mitochondria impairment, i.e. decreases in citrate,uccinate and a-ketoglutarate levels. Methanol/chloroform/wateriver extracts showed a large range of modifications correlated withistological results. In conclusion, this study indicates that urinaryoxicometabonomics could be used to assess target organ drug toxi-ity non-invasively on animal models and identify early biomarkersf liver damage. Moreover, MBX could be also used to evaluateubcellular toxicity like mitochondrial disruptions.
oi:10.1016/j.toxlet.2011.05.939
2316valuation of renal toxicity of melamine, cyanuric acid andheir mixture in F344 neonatal rats
. Woo
Toxicology & Chemistry Division, National Veterinary Research anduarantine Service, Anyang-si, Republic of Korea
Purpose: Both of melamine (2,4,6-triamino-1,3,5-triazine, MEL)nd cyanuric acid (CYA) can be found in food because of widese and existence in mixed forms in environment. This study was
05S (2011) S180–S300 S277
conducted to compare the potency of renal toxicity among MEL,CYA and Mel + Cya using novel biomarkers for the renal toxicity inneonatal rats. Methods: One-day-old male and female neonatal rats(Fischer 344/N Slc) were administered with 1% carboxylmethyl-cellulose (CMC, 5 ml/kg bw, vehicle control), MEL (10, 35 and118 mg/kg bw), CYA (150 mg/kg bw), MEL + CYA (0.35, 1, 3.5 mg/kgbw, respectively) via gavage once per day for 4 wks. Blood wascollected from abdominal artery in the next day of the last admin-istration. Urine samples were collected through metabolic cage andstored at −80 ◦C. The concentrations of KIM-1, TIMP-1, VGEF, clus-terin, NGAL and osteopontin for renal cell damage and �2m, GST-�,Calbindin and Cystantin-C for renal function disorders in serum andurine were analyzed using a bio-plex system. Results: TIMP-1 andclusterin in urine were significantly increased by CYA alone andMEL + CYA treatment. TIMP-1 in serum were decreased in male andfemale rats by MEL + CYA (3.5 mg/kg bw). Cystatin-C in serum wasincreased in female rats by 3.5 MEL + CYA. Osteopontin in serumwas decreased in male rats by 3.5 MEL + CYA. Urinary TIMP-1 andclusterin were increased in female rats by CYA and 3.5 MEL + CYA,respectively. Serum TIMP-1, serum osteopontin urinary TIMP-1 andurinary clusterin could be used as sensitive biomarker for the renaltoxicity of MEL+CYA.
doi:10.1016/j.toxlet.2011.05.940
P2317Differential effects of methylazoxymethanol and MK-801administration on learning and memory impairment inSprague Dawley and Wistar Han rats
A. Zmarowski ∗, M. Beekhuijzen, M. Teunissen, H. Emmen
Toxicology, NOTOX B.V., ‘s-Hertogenbosch, The Netherlands
Wistar Han (WH) and Sprague Dawley (SD) rats are the pre-ferred strains for Europe and the US, respectively, though both areacceptable for EU and US test guidelines. Potential differences inbehavioral performance between the strains have not been exten-sively investigated, though unexpected differences between strainscould complicate risk assessment. Learning and memory testingwas conducted within a developmental neurotoxicity study. Threegroups were used for each strain. F0-females received saline or20 mg/kg methylazoxymethanol (MAM; known to produce neuro-pathic and behavioral alterations in offspring) intra-peritoneally ongestation Day15. Animals littered, and offspring were tested in theBiel maze at weaning (PNDs 22–28) or adulthood (PNDs 62–68).On days of testing, animals were given saline or 0.1 mg/kg MK-801,which impairs learning and memory performance. Animals swam‘path A,’ were then switched to an alternative ‘path B,’ and were lastswitched back to ‘path A’ for the memory test. Time to escape themaze and number of errors were quantified. Both strains learnedeach path, both remembered ‘path A’ when tested, and both wereimpaired with MK-801 administration. However, strain differenceswere evident: in general, SD rats learned better than WHs (takingless time and making fewer errors). They were also more impairedwith MAM treatment, with more time and errors than WHs. Con-versely, WH rats were more impaired with MK-801 administration,especially over ‘path B’. In conclusion, these data highlight differ-ences in general test performance and in drug sensitivity between
doi:10.1016/j.toxlet.2011.05.941
