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calmodulin-dependent protein kinase II, protein kinase C in rats nerve tissues
Abstracts / Toxicology Letters 180S (2008) S32–S246
Symptoms: unconsciousness, hypotension, bradycardia, atrioventricular block, metabolic acidosis, azotemia, electrolytic disorder and dehydration. She received intensive supportive and antidote therapy. Nevertheless, the old women experienced aggravation with respiratory arrest. She died 3 days after admission. After autopsy the samples of parenchymal organs, blood and urine were send for toxicological and histopathological analysis. Toxicological findings: Verapamil was identified and quantified in all samples by GC/MS technique, in the following concentrations: brain 0.05 mg/kg; stomach 0.11 mg/kg; heart, lung and spleen 0.37 mg/kg; kidney with gall bladder 0.06 mg/kg; liver 0.13 mg/kg; small and large intestine 0.16 mg/kg; blood 1.00 mg/L and urine 1.58 mg/L. Histopathological findings: Massive cerebral edema, focal necrosis of cerebellar tissue, pulmonary edema, multiple focal haemorrhages in myocardial tissue, diffuse myocardial lypomathosis and myofibrosis, multiple focal necrosis of hepatic tissue and chronic nephritis. Conclusion: Taking into account the circumstances, clinical picture, autopsy findings and toxicological results of post mortem materials our conclusion was that this was a unnatural death after oral ingestion of large amount of verapamil, a calcium channel blocker agent. doi:10.1016/j.toxlet.2008.06.083 Z61 2,5-Hexanedione (HD) treatment alters Calmodulin, Ca2+ /calmodulin-dependent protein kinase II, protein kinase C in rats nerve tissues Qing-Shan Wang ∗ , Ke-Qin Xie Institute of Toxicology, Shandong University, Jinan, China Recent studies have implicated the involvement of Ca2+ -dependent mechanisms, in particular Ca2+ /calmodulin (CaM)-dependent protein kinase II (CaMKII) in neurotoxin-induced neuropathy. However, it is unknown whether similar mechanisms occur in 2,5hexanedione (HD)-induced neuropathy. For that, we investigated the changes of CaM, CaMKII, protein kinase C (PKC) and polymerization ratios (PR) of NF-L, pNF-M and pNF-H in cerebrum cortex (CC), spinal cord (SC) and sciatic nerve (SN) of rats treated with HD at dosage of 200 or 400 mg/kg for 8 weeks (five times per week). The results showed that CaM contents in CC, SC and SN were significantly increased, which indicated elevation of Ca2+ concentrations in nerve tissues. CaMKII contents and activities were also increased in CC and positively correlated with gait abnormality, but it could not be found in SC and SN. The increases of PKC contents and activities were also observed in SN and positively correlated with gait abnormality. Expect for pNF-M in CC, the polymerization ratios of NFs were also elevated, which were consistent with the activation of protein kinases. The results suggested that CaMKII might be partly (in CC but not in SC and SN) involved in HD-induced neuropathy. CaMKII and PKC might alter the NFs phosphorylation status and polymerization ratios to mediate the HD neurotoxicity. doi:10.1016/j.toxlet.2008.06.084
S245
Z62 Hepatic vitamin A reduction and CYP1A1 induction in rat offspring exposed to several dioxin-like compounds exclusively via lactation Emma Westerholm ∗ , Mattias Öberg, Helen Håkansson Karolinska Institutet, Stockholm, Sweden Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) are ubiquitous contaminants in human tissues and milk. The accumulated maternal exposure is mobilised during breast-feeding and lactational exposure constitutes the quantitatively largest intake in relation to body weight of dioxin-like compounds throughout life. Early postnatal development is known to be vulnerable to exposure of dioxin-like compounds. The study aim was to assess hepatic vitamin A (HVA) reduction and CYP1A1 induction in offspring exposed to dioxin-like compounds exclusively via lactation. Dams were given single oral doses of TCDD, PCDDs, PCDFs, and PCBs within 24 h of delivery. Offspring were exposed via lactation until weaning. Dose–response relationships were observed for both HVA reduction and CYP1A1 induction in offspring after TCDD exposure. Effects were established at similar dose levels for both HVA reduction and CYP1A1 induction, with the 5% effect levels being reached at 0.05 and 0.001 g/kg BW respectively. About 70% of the offspring HVA stores were depleted at the highest TCDD dose. HVA reduction was also significant for CB 105, 126, and 169 with levels reduced about 50%. No significant HVA reductions were observed for the other congeners tested. Significant CYP1A1 induction was observed for all congeners tested, except CB77 previously reported to undergo fast metabolism, and reached a maximum of 30% that of TCDD at comparable doses. Both HVA reduction and CYP1A1 induction in offspring is markedly affected by TCDD exposure at similar dose levels. For the other congeners, different patterns are observed in ability to influence HVA reduction and CYP1A1 induction. doi:10.1016/j.toxlet.2008.06.085 Z63 Comparative study of specific inhibition of bcr-abl gene expression by chemically small interfering RNA and vector expression SiRNA Ali Zaree Mahmodabady ∗ , Ali Najafi, Mehdi Kamali, Hamid Javadi, Ali Khoshbaten Baqyatallah University, Tehran, Islamic Republic of Iran Small interfering RNAs (siRNAs) were designed and chemically synthesised to target the bcr-abl oncogene, which causes chronic myeloid leukemia (CML) and bcr-abl-positive acute lymphoblastic leukemia (ALL) and a different ShRNA sequence were designed for a3b2 and cloned in expression vector. Chemically synthesized anti-bcr-abl siRNAs were selected using reporter gene constructs and were found to reduce transiently bcr-abl mRNA up to 75% in bcr-abl-positive cell lines and in primary cells from CML patients
Symptoms: unconsciousness, hypotension, bradycardia, atrioventricular block, metabolic acidosis, azotemia, electrolytic disorder and dehydration. She received intensive supportive and antidote therapy. Nevertheless, the old women experienced aggravation with respiratory arrest. She died 3 days after admission. After autopsy the samples of parenchymal organs, blood and urine were send for toxicological and histopathological analysis. Toxicological findings: Verapamil was identified and quantified in all samples by GC/MS technique, in the following concentrations: brain 0.05 mg/kg; stomach 0.11 mg/kg; heart, lung and spleen 0.37 mg/kg; kidney with gall bladder 0.06 mg/kg; liver 0.13 mg/kg; small and large intestine 0.16 mg/kg; blood 1.00 mg/L and urine 1.58 mg/L. Histopathological findings: Massive cerebral edema, focal necrosis of cerebellar tissue, pulmonary edema, multiple focal haemorrhages in myocardial tissue, diffuse myocardial lypomathosis and myofibrosis, multiple focal necrosis of hepatic tissue and chronic nephritis. Conclusion: Taking into account the circumstances, clinical picture, autopsy findings and toxicological results of post mortem materials our conclusion was that this was a unnatural death after oral ingestion of large amount of verapamil, a calcium channel blocker agent. doi:10.1016/j.toxlet.2008.06.083 Z61 2,5-Hexanedione (HD) treatment alters Calmodulin, Ca2+ /calmodulin-dependent protein kinase II, protein kinase C in rats nerve tissues Qing-Shan Wang ∗ , Ke-Qin Xie Institute of Toxicology, Shandong University, Jinan, China Recent studies have implicated the involvement of Ca2+ -dependent mechanisms, in particular Ca2+ /calmodulin (CaM)-dependent protein kinase II (CaMKII) in neurotoxin-induced neuropathy. However, it is unknown whether similar mechanisms occur in 2,5hexanedione (HD)-induced neuropathy. For that, we investigated the changes of CaM, CaMKII, protein kinase C (PKC) and polymerization ratios (PR) of NF-L, pNF-M and pNF-H in cerebrum cortex (CC), spinal cord (SC) and sciatic nerve (SN) of rats treated with HD at dosage of 200 or 400 mg/kg for 8 weeks (five times per week). The results showed that CaM contents in CC, SC and SN were significantly increased, which indicated elevation of Ca2+ concentrations in nerve tissues. CaMKII contents and activities were also increased in CC and positively correlated with gait abnormality, but it could not be found in SC and SN. The increases of PKC contents and activities were also observed in SN and positively correlated with gait abnormality. Expect for pNF-M in CC, the polymerization ratios of NFs were also elevated, which were consistent with the activation of protein kinases. The results suggested that CaMKII might be partly (in CC but not in SC and SN) involved in HD-induced neuropathy. CaMKII and PKC might alter the NFs phosphorylation status and polymerization ratios to mediate the HD neurotoxicity. doi:10.1016/j.toxlet.2008.06.084
S245
Z62 Hepatic vitamin A reduction and CYP1A1 induction in rat offspring exposed to several dioxin-like compounds exclusively via lactation Emma Westerholm ∗ , Mattias Öberg, Helen Håkansson Karolinska Institutet, Stockholm, Sweden Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) are ubiquitous contaminants in human tissues and milk. The accumulated maternal exposure is mobilised during breast-feeding and lactational exposure constitutes the quantitatively largest intake in relation to body weight of dioxin-like compounds throughout life. Early postnatal development is known to be vulnerable to exposure of dioxin-like compounds. The study aim was to assess hepatic vitamin A (HVA) reduction and CYP1A1 induction in offspring exposed to dioxin-like compounds exclusively via lactation. Dams were given single oral doses of TCDD, PCDDs, PCDFs, and PCBs within 24 h of delivery. Offspring were exposed via lactation until weaning. Dose–response relationships were observed for both HVA reduction and CYP1A1 induction in offspring after TCDD exposure. Effects were established at similar dose levels for both HVA reduction and CYP1A1 induction, with the 5% effect levels being reached at 0.05 and 0.001 g/kg BW respectively. About 70% of the offspring HVA stores were depleted at the highest TCDD dose. HVA reduction was also significant for CB 105, 126, and 169 with levels reduced about 50%. No significant HVA reductions were observed for the other congeners tested. Significant CYP1A1 induction was observed for all congeners tested, except CB77 previously reported to undergo fast metabolism, and reached a maximum of 30% that of TCDD at comparable doses. Both HVA reduction and CYP1A1 induction in offspring is markedly affected by TCDD exposure at similar dose levels. For the other congeners, different patterns are observed in ability to influence HVA reduction and CYP1A1 induction. doi:10.1016/j.toxlet.2008.06.085 Z63 Comparative study of specific inhibition of bcr-abl gene expression by chemically small interfering RNA and vector expression SiRNA Ali Zaree Mahmodabady ∗ , Ali Najafi, Mehdi Kamali, Hamid Javadi, Ali Khoshbaten Baqyatallah University, Tehran, Islamic Republic of Iran Small interfering RNAs (siRNAs) were designed and chemically synthesised to target the bcr-abl oncogene, which causes chronic myeloid leukemia (CML) and bcr-abl-positive acute lymphoblastic leukemia (ALL) and a different ShRNA sequence were designed for a3b2 and cloned in expression vector. Chemically synthesized anti-bcr-abl siRNAs were selected using reporter gene constructs and were found to reduce transiently bcr-abl mRNA up to 75% in bcr-abl-positive cell lines and in primary cells from CML patients